Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/0091—Signalling for the administration of the divided path, e.g. signalling of configuration information
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
  • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
  • H04L1/0028—Formatting
  • H04L1/003—Adaptive formatting arrangements particular to signalling, e.g. variable amount of bits
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
  • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
  • H04L1/0027—Scheduling of signalling, e.g. occurrence thereof
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
  • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
  • H04L1/0028—Formatting
  • H04L1/0031—Multiple signaling transmission
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0053—Allocation of signalling, i.e. of overhead other than pilot signals
  • H04L5/0057—Physical resource allocation for CQI

Definitions

• the present invention relates to an apparatus, a method, a system, and a computerprogramproduct related to channel state indicators . More particularly, the present invention relates to an apparatus, a method, a system, and a computer program product for aperiodic CSI feedback triggering.
• CSI-RS resource A combination of CSI-RS parameters
• CoMP typically requires significant overhead with respect to reference signals for channel estimation in a multi cellular environment and generates significant overhead for feedback of channel state information (CSI) information.
• CSI channel state information
• the signal processing complexity is quite high. This effort is typically only worth if rewarded by significant gains in terms of spectral efficiency or cell edge performance.
• 2-bit CSI request field will be used in DCI format 0 (if in UE SS) and DCI format 4 for triggering of aperiodic CoMP feedback
• the candidate CSI reports are configured by RRC
• 1-bit CSI request remains in format 0 in the case of CSS ⁇ PFS the payload content of the report
• the CSI request field become 2 bits, where some status is used to indicate for which cell (or which sub-set of cells) the CSI should be reported.
• CA framework will be reused to trigger the aperiodical CSI feedback. That means CSI request field will be reused for CoMP.
• a combination of CA+ CoMP makes the situation extremely complicated, because the UE might be aggregated with multiple CC and multiple CSI-RS resources simultaneously. How to efficiently reuse the request field is a big problem to be solved.
• CSI request field has 2 bits, otherwise it has only 1 bit.
• CSIs may be grouped into sets of CSIs.
• eNB may use RRC signaling to configure sets of CSI processes (i.e. processes comprising measuring CSI and providing the measurement result; in this document, CSI and CSI process are used synonymously, if not otherwise clear from the context) .
• RRC signaling i.e. processes comprising measuring CSI and providing the measurement result; in this document, CSI and CSI process are used synonymously, if not otherwise clear from the context
• eNB has full freedom to configure any CSI processes in any set. No specified mapping rules apply. For example, using higher layer signaling, e.g. RRC signaling, eNB may configure 3 sets of CSI processes. Each set could include 1 or more CSI processes. E.g. one set could include CSI process 1, 3, 4, 5. Another set could include 3 and 4, and a 3rd set might only include CSI process 1.
• an apparatus comprising determining means adapted to determine a size of a request field; deciding means adapted to decide, for each set of channel state indicators configured in a terminal, if the channel state indicators of the respective configured set are to be requested, wherein either all or none of the channel state indicators of the respective configured set are to be requested, and wherein the deciding means is adapted to decide for not more than a maximum number of configured sets that they are to be requested, wherein the maximum number corresponds to the determined size; providing means adapted to provide, to the terminal, the request field with the determined size indicating all configured sets for which the deciding means decided to request the respective channel state indicators.
• the apparatus may further comprise signaling means adapted to signal, to the terminal, the size of the request field.
• the size of the request field may depend on a number of the configured channel state indicators.
• determining processor adapted to determine a size of a request field
• deciding processor adapted to decide, for each set of channel state indicators configured in a terminal, if the channel state indicators of the respective configured set are to be requested, wherein either all or none of the channel state indicators of the respective configured set are to be requested, and wherein the deciding processor is adapted to decide for not more than a maximum number of configured sets that they are to be requested, wherein the maximum number corresponds to the determined size; providing processor adapted to provide, to the terminal, the request field with the determined size indicating all configured sets for which the deciding processor decided to request the respective channel state indicators .
• the apparatus may further comprise signaling processor adapted to signal, to the terminal, the size of the request field.
• the size of the request field may depend on a number of the configured channel state indicators.
• a base station comprising an apparatus according to any of the first and second aspects.
• an apparatus comprising determining means adapted to determine a size of a received request field, extracting means adapted to extract the received request field from a received signal taking into account the determined size; evaluating means adapted to evaluate the extracted request field in order to obtain requested sets, wherein the request field indicates the requested Bets of one ormore configuredsets intowhichoneormore configuredchannel state indicators are grouped; measuring means adapted to measure all channel state indicators of the requested sets.
• the determiningmeans maybe adapted to determine the size of the request field by determining a number of the configured channel state indicators and to determine the size of the request field corresponding to the number of the configured channel state indicators.
• the determining means may be adapted to determine the size of the request fieldbased on a received indication signal .
• an apparatus comprising determining processor adapted to determine a size of a received request field, extractingprocessor adapted to extract the receivedrequest fieldfromareceived signal taking into account the determined size; evaluating processor adapted to evaluate the extracted request field in order to obtain requested sets, wherein the request field indicates the requested sets of one ormore configuredsets into whichone ormore configured channel state indicators are grouped; measuring processor adapted to measure all channel state indicators of the requested sets.
• the determining processor may be adapted to determine the size of the request field by determining a number of the configured channel state indicators and to determine the size of the request field corresponding to the number of the configured channel state indicators. In the apparatus, the determining processor may be adapted to determine the size of the request field based on a received indication signal.
• a terminal comprising an apparatus according to any of the fourth and fifth aspects.
• a method comprisingdetermininga size of a request field; deciding, for each set of channel state indicators configured in a terminal , if the channel state indicators of the respective configured set are to be requested, wherein either all or none of the channel state indicators of the respective configured set are to be requested, and wherein it is decided for not more than a maximum number of configured sets that they are to be requested, wherein the maximum number corresponds to the determined size; providing, to the terminal, the request field with the determined size indicating all configured sets for which it is decided to request the respective channel state indicators.
• the method may be a method of CSX feedback triggering.
• the method may further comprise signaling, to the terminal, the size of the request field.
• the size of the request field may depend on a number of the configured channel state indicators.
• the method may be a method of CSI feedback triggering.
• the determining may comprise determining the size of the request field by determining a number of the configured channel state indicators and determining the size of the request field corresponding to the number of the configured channel state indicators .
• the determining may comprise determining the size of the request field based on a received indication signal.
• the average CSI request length is reduced.
• the payload on PDCCH is reduced.
• a lower coding rate may be converted to lower aggregation level, which means less eCCE are used. Though this coding gain may be quite small (in some cases, only 1 bit is saved) , it is not negligible in general. Due to less payload on the DCI, a larger coverage may be achieved. In detail, the coverage of the control channel is depends on the maximum number of REs used for one control message and the payload of one control signaling. If the number of payload bits is reduced, the coverage may be enhanced.
• control signaling in LTE - like signaling of UL grants DCI 0 and 4 - is transmitted on PDCCH and the system has to ensure a very safe detection of PDCCHs by all UEs in the cell area.
• the size of the PDCCH directed to a certain UE depends on the payload size of the control information (DCI) and the effective coding rate .
• the coding rate on PDCCH is adapted by selecting the aggregation level on PDCCH such that it is suitable to the channel conditions, where the aggregation level determines the number of CCEs or eCCEs on PDCCH. But selection of aggregation levels allows only for a very coarse adjustment of the coding rate which may lead to rather inefficient usage of available PDCCH resources.
• FIG. 1 shows an apparatus according to an embodiment of the invention
• Fig.2 shows a method according to an embodiment of the invention
• Fig.3 shows anapparatus according toanembodimentof the invention
• Fig.4 shows a method according to an embodiment of the invention.
• eNB can configure the size of CSI request field using UE specific RRC signalling, e.g. whether it is 1, 2 or 3 bits or even more bits in the CSI request field.
• the maximum size of the CSI request field may be e.g. 3 bits.
• the size may depend on e.g. the number of configured CSIs, or on the number of CSIs that could be grouped together for feedback.
• Method 2 (implicit way) : the size of CSI request field is decided by the number of configured CSI (across all configured CC) or configured sets of CSIs.
• a number of bits in the CSI request field may be the same as the number of configured CSIs or the number of configured sets.
• the number of configured CSIs is the same as the number of sets into which the configured CSIs are grouped if each set comprises exactly one configured CSI and each configured CSI is comprised in exactly one set. Inother embodiments, thenumberof configuredsetsmaybe different . If the number of configured sets is higher than the number of bits in the CSI request field, only some of the sets may be triggered by the CSI request field. For example, if 7 sets are defined and the CSI request field has 2 bits, only two sets (e.g. the first two sets or the last two sets) may be triggered by the CSI request field, the other five sets not. Thus, the number of triggerable sets (sets whose CSIs may be triggered by the CSI request field) is independent from the number of configured sets. However, in these embodiments, the UE must be informed about the size of the CSI request field. This may be done by the explicit way (Method 1) , or, according to some embodiments, in the following way:
• Table 1 Example of correlation of size of CSI request field and number of configured CSIs
• This method has the advantage that no additional signalling of the size of the CSI request field is required. On the other hand, the UE has to calculate the size of the CSI request field.
• Fig.1 shows anapparatus accordingto anembodiment of the inventio .
• the apparatus may be a base station such as a NodeB or an eNodeB .
• Fig.2 shows a method according to an embodiment of the invention.
• the apparatus according to Fig. 1 may perform the method of Fig. 2 but is not limited to this method.
• the method of Fig. 2 may be performed by the apparatus of Fig. 1 but is not limited to being performed by this apparatus.
• the apparatus comprises determining means 10, deciding means 20, and providing means 30.
• the determiningmeans 10 determines a size of a request field (S10) .
• the size of the request field may depend on the number of configured channel state indicators.
• the apparatus comprises determining means 110, extracting means 120, evaluating means 130, and measuring means 140.
• Achannel state indication gives feedback about a state of a certain channel, in particular a downlink channel.
• a channel state information is specified inLTE.
• other information relevant for estimating a state of a channel may be comprised in the channel state information.
• channel state information may comprise a subset of the specified information only.
• a terminal may comprise any kind of terminal that may be connected to a base station of the respective RAT such as user equipment, mobile phone, PDA, laptop, smartphone etc.
• a base station may comprise any kind of base stations of the respective RAT such as NodeB, eNodeB, pico cell, femto cell, wireless access point etc. If not otherwise stated or otherwise made clear from the context, the statement that two entities are different means that they are differently addressed in the core network. It does not necessarily mean that they are based on different hardware. That is, each of the entities described in the present description may be based on a different hardware, or some or all of the entities may be based on the same hardware.
• exemplary embodiments of the present invention provide, for example a terminal suchas auser equipment, or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program(s) controlling and/or operating the same as well as mediums carrying such computer program(s) and forming computer program product (s) .

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• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Quality & Reliability (AREA)
• Mobile Radio Communication Systems (AREA)

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Citations (3)

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• 2012
  • 2012-08-01 EP EP12882377.0A patent/EP2880796A4/fr not_active Withdrawn
  • 2012-08-01 WO PCT/CN2012/079506 patent/WO2014019169A1/fr not_active Ceased

Patent Citations (4)

Non-Patent Citations (2)

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