WO2021046784A1

WO2021046784A1 - Apparatuses and methods for providing and receiving feedback information

Info

Publication number: WO2021046784A1
Application number: PCT/CN2019/105519
Authority: WO
Inventors: Dong Li; Yong Liu
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2021-03-18
Anticipated expiration: 2022-03-12
Also published as: CN114365561A; CN114365561B

Abstract

Disclosed are apparatuses and methods for providing and receiving feedback information. An example apparatus may be configured to generate a first sequence and a second sequence for feedback information and to map the generated first sequence and the generated second sequence to corresponding subcarriers of a first symbol and a second symbol of an associated physical channel for transmission. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient.

Description

APPARATUSES AND METHODS FOR PROVIDING AND RECEIVING FEEDBACK INFORMATION

TECHNICAL FIELD

Various example embodiments relate to apparatuses and methods for providing and receiving feedback information.

BACKGROUND

Sidelink has been introduced for D2D (Device to Device) communication by 3GPP so that two or more devices or user equipment, such as mobile phones and vehicles, are enabled to communicate with each other directly, for example without much involvement of a base station. It has been agreed that in 3GPP Rel-16, New Radio (NR) sidelink for Vehicle-to-everything (V2X) will support unicast, groupcast and broadcast sidelink transmissions. In the scenario of groupcast, a transmitter device transmits data to a group of receiver devices and the receiver devices could feed back the data decoding status information to the transmitter device. However, the current 3GPP Rel-15 specification does not support the groupcast sidelink transmission with any acknowledgement mechanism for the sidelink communication.

SUMMARY

In a first aspect, example embodiments of an apparatus are disclosed. The apparatus may include at least one processor and at least one memory. The at least one memory may include computer program code, and the at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform the following acts. The acts may include determining feedback information in response to decoding status of received data and generating a first sequence and a second sequence for the feedback information. The first sequence and the second sequence may correspond to a first symbol and a second symbol for an associated physical channel, respectively. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The acts may further include mapping the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission thereon.

In some example embodiments, one of the first sequence and the second sequence may be weighted by the random weighting coefficient, and the other of the first sequence and the second sequence may be weighted by a predetermined weight coefficient.

In some example embodiments, the first sequence may be weighted by a first random weighting coefficient, and the second sequence may be weighted by a second random weighting coefficient.

In some example embodiments, the first sequence may include a plurality of first sub-sequences, and the second sequence may include a plurality of second sub-sequences corresponding to the plurality of first sub-sequences, respectively.

For example, in some example embodiments, the plurality of first sub-sequences may be identical to each other before weighting, and the plurality of second sub-sequences may be identical to each other before weighting.

For example, in some example embodiments, at least two of the plurality of first sub-sequences may be different from each other before weighting, and at least two of the plurality of second sub-sequences may be different from each other before weighting.

For example, in some example embodiments, at most one of the plurality of first sub-sequences may be weighted by a predetermined weighting coefficient, the others of the plurality of first sub-sequences may be weighted by random weighting coefficients separately determined for each of the others of the plurality of first sub-sequences, and each of the plurality of second sub-sequences may be weighted by the same weighting coefficient as that for the corresponding first sub-sequence.

In some example embodiments, the random weighting coefficient may be randomly selected from a set of predefined, configured or preconfigured weighting coefficients.

In some example embodiments, the feedback information may include Hybrid Automatic Repeat reQuest (HARQ) feedback. The first symbol of the associated physical channel may be used to enable automatic gain control (AGC) settling and/or to convey the HARQ feedback, and the second symbol of the associated physical channel may be used to convey the HARQ feedback.

For example, in some example embodiments, the first sequence corresponding to the AGC related symbol may have a length half of a length of the second sequence and may be mapped to every other subcarrier occupied by the second sequence.

In some example embodiments, the first sequence may be based on a first base sequence indexed by a first base sequence index, the second sequence may be based on a second base sequence indexed by a second base sequence index, and the second base sequence index may be associated with the first base sequence index.

For example, in some example embodiments, the second base sequence index may be equal to the first base sequence index.

In a second aspect, example embodiments of an apparatus are disclosed. The apparatus may include at least one processor and at least one memory. The at least one memory may include computer program code, and the at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform the following acts. The acts may include receiving a feedback signal including one or more feedback channels containing feedback information combined over air. The feedback channel may include a first symbol conveying a first sequence and a second symbol conveying a second sequence. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The acts may further include performing a non-coherent detection on the received feedback signal to decode the feedback information.

In a third aspect, example embodiments of a method for providing feedback information are disclosed. The method may include determining feedback information in response to a decoding status of received data and generating a first sequence and a second sequence for the feedback information. The first sequence and the second sequence may correspond to a first symbol and a second symbol for an associated physical channel, respectively. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The method may further include mapping the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission thereon.

In some example embodiments, the feedback information may include Hybrid Automatic Repeat reQuest (HARQ) feedback. The first symbol of the associated physical channel may be used to enable AGC settling and/or to convey the HARQ feedback, and the second symbol of the associated physical channel may be used to convey the HARQ feedback.

In a fourth aspect, example embodiments of a method for receiving feedback information are disclosed. The method may include receiving a feedback signal including one or more feedback channels containing feedback information combined over air. The feedback channel may include a first symbol conveying a first sequence and a second symbol conveying a second sequence. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The method may further include performing a non-coherent detection on the received feedback signal to decode the feedback information.

In a fifth aspect, example embodiments of a computer readable medium are disclosed. The computer readable medium may have instructions stored thereon. The instructions, when executed by at least one processor of an apparatus, may cause the apparatus to perform any one of the above methods.

In a sixth aspect, example embodiments of an apparatus are disclosed. The apparatus may include a determining circuitry, a generating circuitry, and a mapping circuitry. The determining circuitry may be configured to determine feedback information in response to a decoding status of received data. The generating circuitry may be configured to generate first and second sequences for the feedback information. The first sequence and the second sequence may correspond to a first symbol and a second symbols for an associated physical channel, respectively. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The mapping circuitry may be configured to map the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission thereon.

In some example embodiments, the feedback information includes Hybrid Automatic Repeat reQuest (HARQ) feedback. The first symbol of the associated physical channel may be used to enable AGC settling and/or to convey the HARQ feedback, and the second symbol of the associated physical channel may be used to convey the HARQ feedback.

In a seventh aspect, example embodiments of an apparatus are disclosed. The apparatus may include a receiving circuitry and a detecting circuitry. The receiving circuitry may be configured to receive a feedback signal including one or more feedback channels containing feedback information combined over air. The feedback channel may include a first symbol conveying a first sequence and a second symbol conveying a second sequence. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. The detecting circuitry may be configured to perform a non-coherent detection on the received feedback signal to decode the feedback information.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

Fig. 1 illustrates a schematic diagram of an example environment where one or more example embodiments may be implemented.

Fig. 2 illustrates a schematic structural block diagram of an example apparatus for providing feedback information according to some example embodiments.

Fig. 3 illustrates a flowchart of an example method for providing feedback information according to some example embodiments.

Fig. 4 illustrates a schematic diagram of example sequences being mapped to corresponding subcarriers according to some example embodiments.

Fig. 5 illustrates a schematic functional block diagram of an example apparatus for providing feedback information according to some example embodiments.

Fig. 6 illustrates a flowchart of an example method for receiving feedback information according to some example embodiments.

Fig. 7 illustrates a schematic functional block diagram of an example apparatus for receiving feedback information according to some example embodiments.

Fig. 8 illustrates a schematic interaction diagram of communications between a transmitter device and a receiver device according to some example embodiments.

Fig. 9 illustrates a schematic diagram of example sequences for generating the feedback information according to some example embodiments.

Fig. 10 illustrates a schematic diagram of example sequences for generating the feedback information according to some example embodiments.

Fig. 11 illustrates a schematic diagram of example sequences for generating the feedback information according to some example embodiments.

Fig. 12 illustrates a schematic diagram of example sequences for generating the feedback information according to some example embodiments.

Fig. 13 illustrates a graph showing simulation results of detection error rate according to some examples disclosed herein and some comparative examples.

DETAILED DESCRIPTION

In the scenario of groupcast, a transmitter device may transmit data and/or control information to a plurality of receiver devices, and the plurality of receiver devices may transmit a feedback, for example, a Hybrid Automatic Repeat reQuest (HARQ) feedback, to the transmitter device. Depending on the decoding status of the received data at the receiver devices, HARQ ACK/NACK or NACK-only feedback would be transmitted to the transmitter to acknowledge receipt of the data. One option is that each receiver device will transmit the HARQ feedback on a special resource (time/frequency/code) so that the transmitter can distinguish the different receivers. However, this option requires too many feedback resources especially when the number of group members is large. Another option is that the HARQ feedbacks from the plurality of receiver devices share the same (ACK/NACK-specific) resource. In such a case, the multiple HARQ feedback signals sharing the same resource may be destructively combined over the air due to inherent random property of the radio signal such that the transmitter device receives the feedback signals with bad quality and thus may fail to detect the feedback information.

Various example embodiments of apparatuses and methods for providing and receiving feedback information are disclosed herein. FIG. 1 shows an example environment 100 where one or more example embodiments can be implemented. The example environment 100 may include a plurality of user equipment, such as

devices

110, 120 and 130, which may be a part of a communication network, for example a D2D communication network including for example a V2X (Vehicle-to-Everything) network. The example environment 100 may be covered with a 2G/3G/4G/5G network or without any network coverage.

In the example as shown in FIG. 1, the device 110, currently as a transmitter device, can make a groupcast or multicast transmission to receiver devices including for example the

devices

120 and 130. The device 110 may transmit data on a data channel like Physical Sidelink Share Channel (PSSCH) and/or control information on a control channel like Physical Sidelink Control Channel (PSCCH) to the

receiver devices

120 and 130. In response to a decoding status of the received data on the data channel, the devices 120 and/or 130 may transmit feedback information on a feedback channel such as Physical Sidelink Feedback Channels (PSFCH) to the transmitter device 110.

For example, the devices 120 and/or 130 may send only an HARQ NACK (Negative Acknowledgement) to the transmitter device 110 when they fail to decode the received data packet (aNACK-only scheme) , or they also send an HARQ ACK (Acknowledgement) to the transmitter device 110 when they successfully decode the received data packet (an ACK/NACK scheme) . In some embodiments, the

receiver devices

120, 130 will share the resource (time/frequency/code) to transmit the HARQ feedback to the transmitter device 110. For example, in the NACK-only scheme, all NACK feedbacks may be transmitted on the same resource (time/frequency/code) ; in the ACK/NACK scheme, all ACK feedbacks may share the same resource, and all NACK feedbacks may share the same resource different from the resource for the ACK feedbacks.

In some example embodiments, a feedback channel such as PSFCH may have a sequence-based format, for example, a format similar to or the same as PUCCH (Physical Uplink Control Channel) format 0 defined in NR Rel-15 with one Orthogonal Frequency Division Multiplexing (OFDM) symbol, or may have any other suitable format, for example an X-symbol PSFCH format (e.g. X=2 or more) with a repetition of one-symbol PSFCH format. Multiple feedback channels (e.g. PSFCHs) from different receiver devices may share the same resources such as time, frequency, and code so as to reduce the occupied resources. Accordingly, the feedback channels transmitted by the multiple receiver devices may be combined over the air before arriving at the transmitter device such as the device 110.

FIG. 2 shows an example apparatus 200 according to an example embodiment, which, for example, may be a receiver device such as the

devices

120 and 130, or may be at least a part of a receiver device, or may be equipped, combined with or embodied in a receiver device. Further, the example apparatus 200 may also be at least a part of the transmitter device (e.g. the transmitter device 110) , or may also be equipped, combined with or embodied in the transmitter device, so that the receiver device may also operate as a transmitter device in other communications, for example a groupcast communication initiated by the receiver devices 120 and/or 130.

As shown in FIG. 2, the example apparatus 200 may include at least one processor 210 and at least one memory 220 that may include computer program code 230. The at least one memory 220 and the computer program code 230 may be configured to, with the at least one processor 210, cause the apparatus 200 at least to perform a method for providing feedback information as described below with reference to FIG. 3 and/or a method for receiving feedback information as described below with reference to FIG. 6.

In various example embodiments, the at least one processor 210 in the example apparatus 200 may include, but not limited to, at least one hardware processor, including at least one microprocessor for example a central processing unit (CPU) , a portion of at least one hardware processor, and any other suitable dedicated processor such as those developed based on for example Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . Further, the at least one processor 210 may also include at least one other circuitry or element not shown in FIG. 2, for example a decoding circuitry and a baseband processing circuitry.

In various example embodiments, the at least one memory 220 in the example apparatus 200 may include at least one storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include, but not limited to, for example, a random access memory (RAM) , a cache, and so on. The non-volatile memory may include, but not limited to, for example, a read only memory (ROM) , a hard disk, a flash memory, and so on. Further, the at least memory 220 may include, but are not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

Further, in various example embodiments, the example apparatus 200 may also include at least one other circuitry, element, and interface, for example at least one I/O interface (not shown in FIG. 2) , at least one antenna element, and the like.

In various example embodiments, the circuitries, parts, elements, and interfaces in the example apparatus 200, including the at least one processor 210 and the at least one memory 220, may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and so on.

FIG. 3 shows an example method 300 for providing feedback information for example HARQ feedback according to an example embodiment, the operations of which may be executed by for example the above example apparatus 200 as shown in FIG. 2. For example, the at least one memory 220 and the computer program code 230 in the example apparatus 200 may be configured to, with the at least one processor 210 in the example apparatus 200, cause the apparatus 200 at least to perform the operations of the example method 300.

As shown in FIG. 3, at Block 310, feedback information, for example HARQ feedback information, may be determined in response to decoding status of received data. For example, the

device

120 or 130 as a receiver device in the example of FIG. 1 may receive data or control information from the device 110 via for example a data channel (e.g. PSSCH) or a control channel (e.g. PSCCH) , and may decode the received data (including but not limited to the data on PSSCH and/or the control information on PSCCH) . The feedback information may be determined to indicate an NACK for example in a case of decoding failure of the received data, or an ACK otherwise.

At Block 320, a first sequence corresponding to a first symbol for an associated feedback channel (e.g. a sidelink feedback channel such as PSFCH) and a second sequence corresponding to a second symbol for the associated feedback channel may be generated for the feedback information (e.g. HARQ feedback information) . Herein, at least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. Some examples of the first sequence and the second sequence will be described in detail below with reference to FIGs. 9-12.

At Block 330, the first sequence may be mapped to corresponding subcarriers of the first symbol of the associated feedback channel, and the second sequence may be mapped to corresponding subcarriers of the second symbol of the associated feedback channel. FIG. 4 illustrates a schematic diagram of example sequences being mapped to corresponding subcarriers according to some example embodiments. As shown in FIG. 4, the first sequence 410 is mapped to a sequence of subcarriers, for example SC001, SC002, and so on corresponding to the first symbol, and the second sequence 420 is mapped to the same sequence of subcarriers corresponding to the second symbol. It would be understand that the first symbol and the second symbol could be directly adjacent to each other in the time domain.

In an example embodiment, the first sequence 410 may be based on a first base sequence indexed by a first base sequence index, and the second sequence 420 may be based on a second base sequence indexed by a second base sequence index. The second base sequence index may be associated with the first base sequence index, for example, based on a table indicating predetermined correspondence between the first and second base sequence indexes. In some examples, the second base sequence index may be equal to the first base sequence index.

In various example embodiments, at Block 320 in FIG. 3, weighting at least a portion of one of the first sequence and the second sequence by a random weighting coefficient may include two cases, i.e., weighting in the time domain and weighting in the frequency domain. In the first case, the sequences corresponding to different symbols are weighted by different coefficients, but one sequence is weighted by the same coefficients. In the second case, the first sequence and the second sequence are weighted in the same manner, but their respective positions in the frequency domain are weighted by different coefficients. By weighting the two symbols differently in time domain or in frequency domain, it can mitigate the potential destructive combination effect by reducing greatly the probability that the whole received signals of PSFCH suffer severe destructive combination over the air.. Therefore, the feedback signals combined over the air could be successfully detected with a higher probability.

For example, in an example embodiment, at Block 320 in FIG. 3, one of the first and second sequences may be weighted by the random weighting coefficient, and the other of the first and second sequences may be weighted by a predetermined weight coefficient. For example, the predetermined weight coefficient may have a fixed/constant value. In some examples, the fixed/constant value may be equal to 1, which means that the corresponding sequence may not be weighted. Of course, the fixed/constant value may have other values. In some embodiments, the random weighting coefficient may be randomly selected from a set of predefined, configured or preconfigured weighting coefficients. In some other embodiments, the random weighting coefficient may be randomly generated by, for example, a random generator.

In another example embodiment, at Block 320 in FIG. 3, the first sequence may be weighted by a first random weighting coefficient, and the second sequence may be weighted by a second random weighting coefficient. For example, the first random weighting coefficient and the second random weighting coefficient may be independently randomly selected from a set of predefined, configured or preconfigured weighting coefficients, or may be independently randomly generated by for example a random generator.

With respect to the first and second sequences, in an example embodiment, the first sequence may include a plurality of first sub-sequences, and the second sequence may include a plurality of second sub-sequences corresponding to the plurality of first sub-sequences, respectively.

For example, as shown in FIG. 4, the first sequence 410 may include a plurality of first sub-sequences. The first sub-sequence 411 may correspond to subcarriers from SC001 to SC012, the first sub-sequence 412 may correspond to subcarriers from SC013 to SC024, and the first sub-sequence 413 may correspond to subcarriers from SC025 to SC036, and so on. The second sequence 420 may include a plurality of second sub-sequences corresponding to the first sub-sequences of the first sequence 410, respectively. The second sub-sequence 421 may correspond to the first subsequence 411 and be mapped to subcarriers from SC001 to SC012, the second sub-sequence 422 may correspond to the first subsequence 422 and be mapped to subcarriers from SC013 to SC024, and the second sub-sequence 423 may correspond to the first subsequence 423 and be mapped to subcarriers from SC025 to SC036, and so on.

In an example embodiment, the plurality of first sub-sequences may be the same as each other before weighting, and the plurality of second sub-sequences may be the same as each other before weighting. For example, before weighting, the first sub-sequence 411, the first sub-sequence 412, the first sub-sequence 413, and so on in the first sequence 410 may be the same as each other, and the second sub-sequence 421, the second sub-sequence 422, the second sub-sequence 423, and so on in the second sequence 420 may be the same as each other.

In another example embodiment, at least two of the plurality of first sub-sequences may be different from each other before weighting, and at least two of the plurality of second sub-sequences may be different from each other before weighting. For example, all the first sub-sequences in the first sequence 410 may be different from one another before weighting, and all the second sub-sequences in the second sequence 420 may be different from one another before weighting.

In a case where both the first sequence and the second sequence include a plurality of sub-sequences, at Block 320 in FIG. 3, in an example embodiment, all the first sub-sequences of the first sequence may be weighted by a first weighting coefficient, and all the second sub-sequences of the second sequence may be weighted by a second weighting coefficient, so as to implement time-domain weighting as described above. At most one of the first weighting coefficient and the second weighting coefficient is a predetermined weighting coefficient, and the other is a random weighting coefficient.

In another example embodiment, at Block 320 in FIG. 3, at most one first sub-sequence of the first sequence and the corresponding second-sequence of the second sequence may be weighted by a predetermined weighting coefficient, the other first sub-sequences of the first sequence and the corresponding second-sequences of the second sequence may be weighted by one or more random weighting coefficients that are separately determined. In this way, the first sequence 410 and the second sequence 420 are weighted in frequency domain. For example, the weighting coefficient C1 for the first sub-sequence 411 and the corresponding second sub-sequence 421 in FIG. 4 may be a predetermined weighting coefficient, while the other weighting coefficients, including the weighting coefficient C2 for the first sub-sequence 412 and the corresponding second sub-sequence 422, the weighting coefficient C3 for the first-sequence 413 and the corresponding second sub-sequence 423, and so on, may be random weighing coefficients which are independently determined. It would be understand that any one of the coefficients could be the predetermined weighting coefficient. In some embodiments, all the weighting coefficients are independently determined random weighting coefficients.

In some example embodiments, the first symbol and the second symbol of the associated physical channel both may be configured to convey the same feedback information. In some example embodiments, the first symbol may also serve to enable automatic gain control (AGC) settling. For example, the transmitter device 110 may use the first symbol to adjust receiving power of the feedback signal to a desirable level.

In a case where the first symbol enables for example AGC settling, in an example embodiment, the length of the first sequence corresponding to the first symbol generated at Block 320 in FIG. 3 may be less than the length of the second sequence corresponding to the second symbol. For example, the first sequence may have a length half of a length of the second sequence. Thus, at Block 330 in FIG. 3, the first sequence may be mapped to, for example, every other subcarrier occupied by the second sequence.

For example, at Block 330 in FIG. 3, the first sequence 410 in FIG. 4 corresponding to the AGC related symbol may be mapped to the even numbered subcarriers SC002, SC004 (not shown) , …, SC012, SC014, and so on, and the odd numbered subcarriers SC001, SC003 (not shown) , …, SC011, SC013, and so on may be NULL; or in some other embodiments, the first sequence 410 may be mapped to the odd numbered subcarriers SC001, SC003 (not shown) , …, SC011, SC013, and so on, and the even numbered subcarriers SC002, SC004 (not shown) , …, SC012, SC014, and so on may be NULL. The second sequence 420 in FIG. 4 may still be mapped to both the even and odd numbered subcarriers. In the example, the length of each

first sub-sequence

411, 412 and 413 is a half of the length of the corresponding

second sub-sequence

421, 422 or 423.

By mapping the first sequence to only even or odd numbered subcarriers, the corresponding first symbol will have a repetitive structure in time domain so that a first half of the first symbol could be used for AGC adjusting while a second half of the first symbol could be used to enhance the detection performance of the sidelink feedback channel at the feedback-receiving side (the transmitter device 110) . Thus, a detection performance for the feedback channel would not degrade due to a distortion within the first half of the first AGC-related symbol caused by for example the AGC adjusting.

The apparatus and method of the present disclosure for providing feedback information are not limited to the above example embodiments. For example, as shown in FIG. 5, in lieu of or in addition to the example implementation of the example apparatus 200 as shown in FIG. 1, another example apparatus 500 for providing feedback information according to some example embodiments may include a determining circuitry 510, a generating circuitry 520, and a mapping circuitry 530.

The term “circuitry” throughout this disclosure may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) ; (b) combinations of hardware circuits and software, such as (as applicable) (i) a combination of analog and/or digital hardware circuit (s) with software/firmware and (ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) ; and (c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this disclosure, including in any claims. As a further example, as used in this disclosure, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

In an example embodiment, the determining circuitry 510 in the example apparatus 500 may be configured to determine feedback information (e.g. HARQ feedback information) in response to a decoding status of received data, for example may be configured to perform the operation 310 of the example method 300 in FIG. 3.

In an example embodiment, the generating circuitry 520 in the example apparatus 500 may be configured to generate first and second sequences for the feedback information. The first sequence and the second sequence may correspond to a first symbol and a second symbols for an associated physical channel, respectively, and at least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. For example, the generating circuitry 520 may be configured to perform the operation 320 of the example method 300 in FIG. 3.

In an example embodiment, the mapping circuitry 530 in the example apparatus 500 may be configured to map the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission thereon. For example, the mapping circuitry 530 may be configured to perform the operation 330 of the example method 300 in FIG. 3.

Similar to the example apparatus 200, in various example embodiments, the example apparatus 500 may also include at least one other circuitry, element, and interface, for example at least one I/O interface, at least antenna element, and so on, and the circuitries, parts, elements, and interfaces in the example apparatus 500 may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and so on.

FIG. 6 shows an example method 600 for receiving feedback information such as HARQ feedback according to an example embodiment, operations/steps of which may be executed by for example the above example apparatus 200 as shown in FIG. 2. For example, the at least one memory 220 and the computer program code 230 in the example apparatus 200 may be configured to, with the at least one processor 210 in the example apparatus 200, cause the apparatus 200 at least to perform the operations of the example method 600.

As shown in FIG. 6, at Block 610, a feedback signal including a plurality of feedback channels containing feedback information combined over air may be received. For example, a sidelink HARQ feedback signal including a plurality of sidelink HARQ feedback channels (PSFCHs) containing sidelink HARQ feedback information combined over air may be received.

As described above with reference to the

example apparatus

200 or 500 and the example method 300, a feedback channel (e.g. PSFCH) involved in the example method 600 may include a first symbol conveying a first sequence and a second symbol conveying a second sequence. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient.

At Block 620, detection, for example non-coherent detection, may be performed on the received feedback signal to decode the feedback information. The detection step will be further described in detail below with reference to embodiments shown in FIGs. 9-12.

The apparatus and method of the present disclosure for receiving the feedback information such as HARQ feedback are not limited to the above example embodiments. FIG. 7 shows another example apparatus 700 for receiving the feedback information which includes a receiving circuitry 710 and a detecting circuitry 720.

In an example embodiment, the receiving circuitry 710 in the example apparatus 700 may be configured to receive a feedback signal including a plurality of feedback channels containing feedback information combined over air. For example, the receiving circuitry 710 may be configured to perform the operation 610 of the example method 600 in FIG. 6. In an example embodiment, the detecting circuitry 720 in the example apparatus 700 may be configured to perform detection such as non-coherent detection on the received feedback signal to decode the feedback information. For example, the detecting circuitry 720 may be configured to perform the operation 620 of the example method 600 in FIG. 6.

In various example embodiments, the example apparatus 700 may also include at least one other circuitry, element, and interface, for example at least one I/O interface, at least antenna element, and so on, and the circuitries, parts, elements, and interfaces in the example apparatus 700 may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and so on.

FIG. 8 shows a schematic interaction diagram of communications between a transmitter device 810 (for example, the device 110 in FIG. 1 with the

example apparatus

200 or 700 as shown in FIG. 2 or 7 for implementing the example method 600 as shown in FIG. 6) and a receiver device 820 (for example, the

device

120 or 130 in FIG. 1 with the

example apparatus

200 or 500 as shown in FIG. 2 or 5 for implementing the example method 300 as shown in FIG. 3) .

As shown in FIG. 8, at 815, the transmitter device 810 may make a groupcast or multicast transmission to receiver devices including the receiver device 820. For example, the transmitter device 810 may transmit a data channel for data, including for example a sidelink data channel such as Physical Sidelink Share Channel (PSSCH) , and/or possibly a control channel for control information, including for example a sidelink control channel such as Physical Sidelink Control Channel (PSCCH) , to the receiver devices including the receiver device 820.

In response to a decoding status of the received data on the PSSCH channel, the receiver device 820 may execute for example the operations in the example method 300 as shown in FIG. 3, including the operation 310 for determining feedback information in response to decoding status of received data, the operation 320 for generating a first sequence corresponding to a first symbol of an associated physical channel and a second sequence corresponding to a second symbol of the associated physical channel for the feedback information, and the operation 330 for mapping the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission.

Then, at 825, the receiver device 820 may transmit feedback information on a feedback channel to the transmitter device 910. It should be noted that the feedback channels from a plurality of receiver devices may share the same resource and thus are combined over the air.

As shown in FIG. 8, the transmitter device 810 may execute for example the operation 610 in the example method 600 as shown in FIG. 6 to receive a feedback signal. Here, the feedback signal received by the transmitter device 810 may include a plurality of feedback channels from a plurality of receiver devices 820 that are combined over air.

Then, the transmitter device 810 may execute for example the operation 620 in the example method 600 as shown in FIG. 6 to perform detection for example non-coherent detection on the received feedback signal to decode the feedback information. As the feedback channels from the plurality of receiver devices 820 are respectively weighted according to the method 300 of FIG. 3, the feedback channels combined over the air would not be destructively combined and thus the feedback information would be successfully decoded.

The disclosure is not limited to the above example embodiments. For example, as shown in some example embodiments to be described below, one or more features described above may be for example modified, omitted, and/or combined, and also some additional or alternative features may be introduced and may be combined or replaced with one or more features described above.

FIGs. 9-12 show some example embodiments of the feedback channel formed in the method 300 of FIG. 3. In a first example embodiment shown in FIG. 9, a sidelink feedback channel such as PSFCH may be configured to include two symbols, a first symbol 910 and a second symbol 920. In addition to conveying feedback information, the first symbol 910 may also be used to enable AGC settling. As shown in FIG. 9, the first symbol 910 and the second symbol 920 have the same length and are mapped to N _PSFCH subcarriers, where N _PSFCH may be one or multiple times of the number of subcarriers in a resource block, for example 12, 24, 36, and so on.

The first and

second sequences

910, 920 may be generated by the operation 320 in the method 300 of FIG. 3. In the operation 320, a first base sequence index for the first sequence over the first symbol 910 and a second base sequence index for the second sequence over the second symbol 920 may be determined. In the first embodiment, the two indexes may be equal to each other. As an example, the index may be determined as a function of at least the source ID of the groupcast data packet, i.e., the physical layer source ID of the transmitter device 110 in FIG. 1. For example, the index may be determined as u=mod (ID _SRC, M) where ID _SRC denotes a decimal value of the source ID and M denotes a total number of base sequences indexed by the index u, e.g. M=30.

The first sequence and the second sequence may be generated based on the above determined base sequence index u and the feedback information (e.g. HARQ feedback ACK/NACK information) , for example based on the following Equation 1:

wherein

denotes the base sequence indexed by index u and it may be determined according to Physical Uplink Control Channel (PUCCH) format 0, k=0, 1, ..., N _seq-1 is the index of the sequence elements, N _seq denotes the length of the sequence, e.g. N _seq=24,

contains the feedback information, e.g. α=0 for NACK and α=6 for ACK, m denotes the symbol index, e.g. m=0 denotes the first symbol 910 and m=1 denotes the second symbol 920, and n denotes the receiver device index. As seen from the Equation 1, the first sequence before weighting and the second sequence before weighting have the same length and are identical to each other.

In the operation 320 of the method 300, the weighting coefficient w ⁽ⁿ⁾ (m=0) for the first sequence over the first symbol 910 and the weighting coefficient w ⁽ⁿ⁾ (m=1) for the second sequence over the second symbol 920 may be determined based on the following Equation 2 and Equation 3, respectively:

w ⁽ⁿ⁾ (m=0) =1 (Equation 2)

w ⁽ⁿ⁾ (m=1) =e ^j2πp/P (Equation 3)

where the weighting coefficient w ⁽ⁿ⁾ (m=1) may be randomly selected from a predefined, configured or preconfigured weighting coefficient set

P is an integer larger than 1, e.g. P=4, and m=0, 1 denotes the symbol index.

As seen in the first example embodiment, a fixed weighting coefficient may be determined for the first sequence over the first symbol 910, while an opportunistic weighting coefficient may be determined for the second sequence over the second symbol 920. As the fixed weighting coefficient is equal to 1, it means that the first sequence may not be weighted. Of course, the fixed weighting coefficient may also have a fixed value other than 1. In some embodiments, the weighting coefficient w ⁽ⁿ⁾ (m=0) may be randomly selected from a predefined, configured or preconfigured set of weighting coefficients, while w ⁽ⁿ⁾ (m=1) has a fixed value; or both w ⁽ⁿ⁾ (m=0) and w ⁽ⁿ⁾ (m=1) are independently randomly selected from a predefined set of weighting coefficients.

Then, the first and the second sequences may be weighted and mapped to subcarriers over the first and second symbols 1010 and 1020, for example based on the following Equation 4:

where k=0, 1, ..., N _PSFCH-1, N _PSFCH=N _seq denotes the number of the subcarriers occupied by the feedback channel, and m=0, 1 denotes the symbol index.

As shown in FIG. 9, the symbol 910 may convey the first sequence after weighting, and the second symbol 920 may convey the second sequence after weighting.

Then, the feedback channel is transmitted to the transmitter device 110, which may receive the feedback channel by the operations of the method 600. Here, it should be noted that a plurality of feedback channels generated as above at a plurality of receiver devices 120, 130 may be transmitted using the same resource (time/frequency/code) and thus combined over the air. The feedback signal received at 610 of the method 600 at the transmitter device 110 may be expressed as the following Equation 5:

where k=0, 1, ..., N _PSFCH-1, m=0, 1 denotes symbol index, H ⁽ⁿ⁾ denotes the radio channel coefficients between the n-th receiver device and the transmitter device over the radio resource occupied by the feedback channel, and v denotes the noise plus interference.

Then, at the operation 620 in the method 600, non-coherent detection for the feedback sequence through sequence correlation may be performed for example based on the following Equation 6:

where the superscript *denotes a conjugate operation. If the correlation result of Equation 6 exceeds a predetermined threshold value, the feedback is successfully detected, or otherwise the feedback is missed. It would be understood that the above non-coherent detection method is only an example and other detection methods are also possible.

In a second example embodiment shown in FIG. 10, a sidelink feedback channel is also configured to include two symbols, a first symbol 1010 conveying a first sequence and a second symbol 1020 conveying a first sequence. The first symbol may also be used to enable AGC settling. The first sequence

and the second sequence

may be generated based on the following Equations 7-8:

Here, the terms

and

denote the base sequence indexed by u for the first sequence and the second sequence, respectively. It can be seen that the first sequence has a length half of the second sequence.

The weighting coefficient w ⁽ⁿ⁾ (m=0) for the first sequence over the first symbol 1010 and the weighting coefficient w ⁽ⁿ⁾ (m=1) for the second sequence over the second symbol 1020 may be determined in a similar way to the first example embodiment. In some example, a fixed weighting coefficient may be determined for the first sequence over the first symbol 1010, while an opportunistic weighting coefficient may be determined for the second sequence over the second symbol 1020. Then, the first and the second sequences may be weighted and mapped to subcarriers over the first and second symbols 1010 and 1020, for example based on the following Equation 9:

wherein k=0, 1, ..., N _PSFCH-1, N _PSFCH denotes the number of subcarriers of sidelink feedback channel, e.g. N _seq=N _PSFCH=24.

As shown in FIG. 10, as the first sequence has a length half of the second sequence, the former is mapped to every other subcarrier occupied by the second sequence. Although in Equation 9 the first sequence is mapped to even numbered subcarriers, it may also be mapped to odd numbered subcarriers. By mapping the first sequence to only even or odd numbered subcarriers, the corresponding first symbol 1010 will have a repetitive structure in time domain so that a first half of the first symbol 1010 could be used for AGC adjusting while a second half of the first symbol 1010 could be used to enhance the detection performance of the sidelink feedback channel. Thus, a detection performance for the feedback channel would not degrade due to a distortion within the first half of the first AGC-related symbol caused by for example the AGC adjusting. In this embodiment, it should be noted that the first AGC-related symbol conveying the first sequence may have a 3dB power boosting for each used subcarrier compared with the second symbol conveying the second sequence so that the total transmit power would be equal therebetween.

Then, the feedback channel is transmitted to the transmitter device 110, which may receive the feedback channel by the operations of the method 600. Here, it should be noted that a plurality of feedback channels generated as above at a plurality of

receiver devices

120, 130 are transmitted using the same resource (time/frequency/code) and thus combined over the air. The feedback signal received at 610 of the method 600 at the transmitter device 110 may also be expressed as the above Equation 5.

Then at 620 of the method 600, the transmitter device 110 may perform non-coherent detection through sequence correlation for the received first sequence over the first symbol 1010 and the received second sequence over the second symbol 1020. The received first sequence may be obtained for example from a second half of the first symbol 1010 and the first half may be used for AGC adjusting. The non-coherent detection may be based on the following Equation 10:

wherein the superscript *denotes the conjugate operation. If the correlation result of Equation 10 exceeds a predetermined threshold value, the feedback is successfully detected, or otherwise the feedback is missed. It would be understood that the above non-coherent detection method is only an example and other detection methods are also possible.

In a third example embodiment shown in FIG. 11, a sidelink feedback channel may also be configured to include two symbols, a first symbol 1110 conveying a first sequence and a second symbol 1120 conveying a second sequence, and the first symbol 1110 may be configured to enable AGC settling. However, the first sequence on the first symbol 1110 includes at least two repetitions of first sub-sequences arranged in the frequency domain, and the second sequence on the second symbol 1120 also includes at least two repetitions of second sub-sequences arranged in the frequency domain. The first sub-sequences may correspond to the second sub-sequences, respectively.

Then, the first and the second sequences may be weighted and mapped to subcarriers based on the following Equation 11:

wherein

denotes a first sub-sequence (m=0) or a second sub-sequence (m=1) , N _sseq denotes the number of subcarriers occupied by a sub-sequence, e.g. N _sseq= the number of subcarriers per physical resource block (e.g. 12) . Equation 11 only shows two sub-sequences for a sequence. In some other embodiments, each sequence may include more than two sub-sequences.

As shown in FIG. 11, the symbol 1110 may include the first sequence after weighting, the second symbol 1120 may include the second sequence after weighting, and both weighted sequences have the same length. The first sequence includes two repetitions of

first sub-sequences

1230 and 1240, and the second sequence includes two repetitions of

second sub-sequences

1250 and 1260. The first sub-sequence 1230 and the corresponding second sub-sequence 1250 are weighted by the same weighting coefficient w ⁽ⁿ⁾ (0) , and the first sub-sequence 1240 and the corresponding second sub-sequence 1260 are weighted by the same weighting coefficient w ⁽ⁿ⁾ (1) . In this way, the first sequence and the second sequence are weighted in the frequency domain. It should be noted that at most one pair of first and second sub-sequences may be weighted by a predetermined weighting coefficient, and other sub-sequences may be weighted by a random weighting coefficient.

receiver devices

Then, at the operation 620 in the method 600, non-coherent detection for the feedback sequence through sequence correlation may be performed for example based on the following Equation 12:

wherein the superscript *denotes a conjugate operation. Here, it should be noted that the non-coherent detection is only performed on the second symbol as the first symbol is used to enable AGC settling. In some other embodiments, both the first symbol and the second symbol may be used for non-coherent detection. In such a case, a detection performance for the feedback channel might be degraded to some extent due to a distortion within the first symbol caused by for example the AGC adjusting. To alleviate or prevent the detection performance degradation, in some embodiments, the first sequence may have a length half of the second sequence, as in the second embodiment, so that only a second half of the first symbol may be used to improve the detection performance.

It should also be noted that the first and second sequences each may include more than two repetitions of sub-sequences. In some embodiments, the first sub-sequence may have a length half of the second sub-sequence, and the first sub-sequence may be mapped to every other subcarrier occupied by the second sub-sequence. In such a case, a first half of the first symbol may be used to enable AGC settling and a second half may be used to improve the detection performance. Although in the third embodiment the first and second sequences are weighted in the frequency domain, they may also be weighted in the time domain as in the first and second embodiments.

In a fourth example embodiment shown in FIG. 12, a sidelink feedback channel may also be configured to include two symbols, a first symbol 1210 conveying a first sequence and a second symbol 1320 conveying a second sequence. The fourth embodiment of FIG. 12 is similar to the third embodiment of FIG. 11 except that the first sequence and the second sequence each includes only one single sequence, without repetitions of sub-sequences.

The first sequence 1210 and the second sequence 1220 may be weighted in the frequency domain, as shown in the following Equation 13:

where N _per is a weighting period in the frequency domain. For example, every N _per elements of the first/second sequence may be deemed as a "sub-sequence" , though the plurality of "sub-sequences" may not be identical to each other even before weighting, not like in the third embodiment that the sub-sequences are identical to each other before weighting. In some embodiments, N _per may preferably be the number of subcarriers in each physical resource block, i.e., N _per = 12. Then, the first and second sequences may be weighted in the frequency domain, similarly to the third embodiment.

As shown in FIG. 12, the first sequence on the first symbol 1210 may include at least two first segments1230 and 1240, and the second sequence on the second symbol 1220 may include at least two

second segments

1250 and 1260. The first segment 1230 corresponds to the second segment 1250, both of which are weighted by the same weighting coefficient w ⁽ⁿ⁾ (0) . The first segment 1240 corresponds to the second segment 1260, both of which are weighted by the same weighting coefficient w ⁽ⁿ⁾ (1) .

The feedback channel may be transmitted to and received at the transmitter device 110. Similar to the first example embodiment, the feedback signal received at the transmitter device 110 may also be expressed as for example the above Equation 5.

Then, non-coherent detection for the feedback sequence through sequence correlation may be performed for example based on the following Equation 14:

Simulations were made to evaluate the first embodiment mentioned above as compared to some comparative examples in which no weighting is applied. The simulation conditions are listed in the following table and the simulation results are shown in FIG. 13. From the simulation results, it can be observed that under the evaluation conditions, the examples of embodiments in the present disclosure achieve significant performance gains as the number of receivers sharing the feedback resource becomes large.

Table 1

Some example embodiments have been described above. However, the disclosure is not limited to the above example embodiments.

Another example embodiment may relate to a signal generated for example through the above example method 300. For example, the signal may be a sidelink feedback signal or an HARQ feedback signal for example in a sidelink communication, and the signal may include a first sequence and a second sequence corresponding to a first symbol and a second symbol for a associated physical channel, respectively. At least a portion of one of the first sequence and the second sequence may be weighted by a random weighting coefficient. For example, the signal may be a radio signal.

Another example embodiment may relate to computer program codes or instructions which, when executed by at least one processor of an apparatus for example the

above example apparatus

200 or 500 or 700, may cause the apparatus to perform any one of the methods such as the

above example method

300 or 600.

Another example embodiment may be related to a computer readable medium having such computer program codes or instructions stored thereon. In various example embodiments, such a computer readable medium may include at least one storage medium in various forms, for example a volatile memory and/or a non-volatile memory. The volatile memory may include, but not limited to, for example, a random access memory (RAM) , a cache, and so on. The non-volatile memory may include, but not limited to, for example, a read only memory (ROM) , a hard disk, a flash memory, and so on. Further, the at least memory 220 may include, but are not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise, ” “comprising, ” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to. ” The word “coupled” , as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Likewise, the word “connected” , as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein, ” “above, ” “below, ” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

Moreover, conditional language used herein, such as, among others, “can, ” “could, ” “might, ” “may, ” “e.g., ” “for example, ” “such as” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment.

While some example embodiments have been described, these embodiments have been presented by way of example, and are not intended to limit the scope of the disclosure. Indeed, the apparatus, methods, and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. For example, while blocks are presented in a given arrangement, alternative embodiments may perform similar functionalities with different components and/or circuit topologies, and some blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these blocks may be implemented in a variety of different ways. The order of these blocks may also be changed. Any suitable combination of the elements and acts of the various embodiments described above can be combined to provide further embodiments. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

Claims

An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform:

determining feedback information in response to a decoding status of received data;

generating a first sequence and a second sequence for the feedback information, the first sequence and the second sequence corresponding to a first symbol and a second symbol for an associated physical channel, respectively, and at least a portion of one of the first and second sequences being weighted by a random weighting coefficient; and

mapping the first and second sequences to corresponding subcarriers of the first and second symbols of the associated physical channel for transmission thereon.
The apparatus of claim 1 wherein one of the first and second sequences is weighted by the random weighting coefficient, and the other of the first and second sequences is weighted by a predetermined weight coefficient.
The apparatus of claim 1 wherein the first sequence is weighted by a first random weighting coefficient, and the second sequence is weighted by a second random weighting coefficient.
The apparatus of claim 1 wherein the first sequence includes a plurality of first sub-sequences, the second sequence includes a plurality of second sub-sequences corresponding to the plurality of first sub-sequences, respectively.
The apparatus of claim 4 wherein the plurality of first sub-sequences are identical to each other before weighting, and the plurality of second sub-sequences are identical to each other before weighting.
The apparatus of claim 4 wherein at least two of the plurality of first sub-sequences are different from each other before weighting, and at least two of the plurality of second sub-sequences are different from each other before weighting.
The apparatus of claim 4 wherein at most one of the plurality of first sub-sequences is weighted by a predetermined weighting coefficient, the others of the plurality of first sub-sequences are weighted by random weighting coefficients separately determined for each of the others of the plurality of first sub-sequences, each of the plurality of second sub-sequences is weighted by the same weighting coefficient as that for the corresponding first sub-sequence.
The apparatus of claim 1 wherein the random weighting coefficient is randomly selected from a set of predefined, configured or preconfigured weighting coefficients.
The apparatus of claim 1 wherein the feedback information includes Hybrid Automatic Repeat reQuest (HARQ) feedback, the first symbol of the associated physical channel is used to enable automatic gain control (AGC) settling and/or convey the HARQ feedback, and the second symbol of the associated physical channel is used to convey the HARQ feedback .
The apparatus of claim 9 wherein the first sequence corresponding to the AGC related symbol has a length half of a length of the second sequence and is mapped to every other subcarrier occupied by the second sequence.
The apparatus of claim 1 wherein the first sequence is based on a first base sequence indexed by a first base sequence index, the second sequence is based on a second base sequence indexed by a second base sequence index, and the second base sequence index is associated with the first base sequence index.
The apparatus of claim 11 wherein the second base sequence index is equal to the first base sequence index.
An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform:

receiving a feedback signal including one or more feedback channels containing feedback information combined over air, the feedback channel comprising a first symbol conveying a first sequence and a second symbol conveying a second sequence, at least a portion of one of the first sequence and the second sequence being weighted by a random weighting coefficient ; and

performing a non-coherent detection on the received feedback signal to decode the feedback information.
A method for providing feedback information comprising:

determining feedback information in response to a decoding status of received data;

generating a first sequence and a second sequence for the feedback information, the first sequence and the second sequence corresponding to a first symbol and a second symbol for an associated physical channel, respectively, and at least a portion of one of the first and second sequences being weighted by a random weighting coefficient; and

mapping the first and second sequences to corresponding subcarriers of the first and second symbols of the associated physical channel for transmission thereon.
The method of claim 14 wherein one of the first and second sequences is weighted by the random weighting coefficient, and the other of the first and second sequences is weighted by a predetermined weight coefficient.
The method of claim 14 wherein the first sequence is weighted by a first random weighting coefficient, and the second sequence is weighted by a second random weighting coefficient.
The method of claim 14 wherein the first sequence includes a plurality of first sub-sequences, the second sequence includes a plurality of second sub-sequences corresponding to the plurality of first sub-sequences, respectively.
The method of claim 17 wherein at most one of the plurality of first sub-sequences is weighted by a predetermined weighting coefficient, the others of the plurality of first sub-sequences are weighted by random weighting coefficients separately determined for each of the others of the plurality of first sub-sequences, each of the plurality of second sub-sequences is weighted by the same weighting coefficient as that for the corresponding first sub-sequence.
The method of claim 14 wherein the feedback information includes Hybrid Automatic Repeat reQuest (HARQ) feedback, the feedback information includes Hybrid Automatic Repeat reQuest (HARQ) feedback, the first symbol of the associated physical channel is used to enable automatic gain control (AGC) settling and/or convey the HARQ feedback, and the second symbol of the associated physical channel is used to convey the HARQ feedback .
The method of claim 19 wherein the first sequence corresponding to the AGC related symbol has a length half of a length of the second sequence and is mapped to every other subcarrier occupied by the second sequence.
A method for receiving feedback information comprising:

receiving a feedback signal including one or more feedback channels containing feedback information combined over air, the feedback channel comprising a first symbol conveying a first sequence and a second symbol conveying a second sequence, at least a portion of one of the first sequence and the second sequence being weighted by a random weighting coefficient; and

performing a non-coherent detection on the received feedback signal to decode the feedback information.
A computer readable medium having instructions stored thereon, the instructions, when executed by at least one processor of an apparatus, causing the apparatus to perform the method of any one of claims 14-21.
An apparatus comprising:

a determining circuitry configured to determine feedback information in response to a decoding status of received data;

a generating circuitry configured to generate a first sequence and a second sequence for the feedback information, the first sequence and the second sequence corresponding to a first symbol and a second symbols for an associated physical channel, respectively, and at least a portion of one of the first sequence and the second sequence being weighted by a random weighting coefficient; and

a mapping circuitry configured to map the first sequence and the second sequence to corresponding subcarriers of the first symbol and the second symbol of the associated physical channel for transmission thereon.
The apparatus of claim 23 wherein one of the first sequence and the second sequence is weighted by the random weighting coefficient, and the other of the first sequence and the second sequence is weighted by a predetermined weight coefficient.
The apparatus of claim 23 wherein the first sequence is weighted by a first random weighting coefficient, and the second sequence is weighted by a second random weighting coefficient.
The apparatus of claim 23 wherein the first sequence includes a plurality of first sub-sequences, and the second sequence includes a plurality of second sub-sequences corresponding to the plurality of first sub-sequences, respectively.
The apparatus of claim 26 wherein the plurality of first sub-sequences are identical to each other before weighting, and the plurality of second sub-sequences are identical to each other before weighting.
The apparatus of claim 26 wherein at least two of the plurality of first sub-sequences are different from each other before weighting, and at least two of the plurality of second sub-sequences are different from each other before weighting.
The apparatus of claim 26 wherein at most one of the plurality of first sub-sequences is weighted by a predetermined weighting coefficient, the others of the plurality of first sub-sequences are weighted by random weighting coefficients separately determined for each of the others of the plurality of first sub-sequences, and each of the plurality of second sub-sequences is weighted by the same weighting coefficient as that for the corresponding first sub-sequence.
The apparatus of claim 23 wherein the random weighting coefficient is randomly selected from a set of predefined, configured or preconfigured weighting coefficients.
The apparatus of claim 23 wherein the feedback information includes Hybrid Automatic Repeat reQuest (HARQ) feedback, the first symbol of the associated physical channel is used to enable AGC settling and/or to convey the HARQ feedback, and the second symbol of the associated physical channel is used to convey the HARQ feedback.
The apparatus of claim 31 wherein the first sequence corresponding to the AGC related symbol has a length half of a length of the second sequence and is mapped to every other subcarrier occupied by the second sequence.
The apparatus of claim 23 wherein the first sequence is based on a first base sequence indexed by a first base sequence index, the second sequence is based on a second base sequence indexed by a second base sequence index, and the second base sequence index is associated with the first base sequence index.
The apparatus of claim 33 wherein the second base sequence index is equal to the first base sequence index.
An apparatus comprising:

a receiving circuitry configured to receive a feedback signal including one or more feedback channels containing feedback information combined over air, the feedback channel including a first symbol conveying a first sequence and a second symbol conveying a second sequence, at least a portion of one of the first sequence and the second sequence being weighted by a random weighting coefficient; and

a detecting circuitry configured to perform a non-coherent detection on the received feedback signal to decode the feedback information.