WO2025171638A1

WO2025171638A1 - Method and apparatus for irregular reference signal pattern designs in joint communication and sensing

Info

Publication number: WO2025171638A1
Application number: PCT/CN2024/077358
Authority: WO
Inventors: Rui Zhang; Shiau-He Tsai; Wei-Nan Sun
Original assignee: MediaTek Inc
Current assignee: MediaTek Inc
Priority date: 2024-02-18
Filing date: 2024-02-18
Publication date: 2025-08-21
Anticipated expiration: 2026-08-18

Abstract

Various solutions for irregular reference signal (RS) pattern designs in joint communication and sensing are described. A transmitter apparatus may configure one or more RSs to form an irregular RS pattern. Then, the transmitter apparatus may transmit a configuration of the one or more RSs to a receiver apparatus. The configuration indicates time and frequency information related to the irregular RS pattern. Also, the transmitter apparatus may transmit the one or more RSs to the receiver apparatus based on the configuration for a sensing of a target object.

Description

METHOD AND APPARATUS FOR IRREGULAR REFERENCE SIGNAL PATTERN DESIGNS IN JOINT COMMUNICATION AND SENSING

TECHNICAL FIELD

The present disclosure is generally related to mobile communications and, more particularly, to irregular reference signal (RS) pattern designs in joint communication and sensing.

BACKGROUND

Unless otherwise indicated herein, approaches described in this section are not prior art to the claims listed below and are not admitted as prior art by inclusion in this section.

Mobile communication and radar sensing have been advancing independently for decades. Until recently, the coexistence, cooperation, and joint design of the two systems becomes of interest. Motivation for such topic may include that the use of millimeter waves in 5th generation (5G) and beyond leads to an occupation of adjacent frequency bands, which makes the convergence of the frequency bands used by two systems possible. In addition, with the increasing use of radar sensing in consumer devices and automotive applications, radar systems have entered mass markets. Given that jointly handling communications and sensing on the same architecture or platform would be more cost effective and have lower complexity as compared to two independent platforms, the concept of joint communication and sensing is introduced.

Nonetheless, traditional solutions to distance and velocity detection in radar sensing do not consider communication system RS patterns and adapting their configuration parameters for desired distance-velocity ambiguity performance. Accordingly, how to design the RS pattern in joint communication and sensing has become an important issue. Therefore, there is a need to provide proper schemes to address this issue.

SUMMARY

The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce concepts, highlights, benefits and advantages of the novel and non-obvious techniques described herein. Select implementations are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

An objective of the present disclosure is to propose solutions or schemes that address the aforementioned issue pertaining to RS pattern design in joint communication and sensing.

In one aspect, a method may involve a transmitter apparatus configuring one or more RSs to form an irregular RS pattern. The method may also involve the transmitter apparatus transmitting a configuration of the one or more RSs to a receiver apparatus, wherein the configuration indicates time and frequency information related to the irregular RS pattern. The method may further involve the transmitter apparatus transmitting the one or more RSs to the receiver apparatus based on the configuration for a sensing of a target object.

In one aspect, a transmitter apparatus may comprise a transceiver which, during operation, wirelessly communicates with a receiver apparatus. The transmitter apparatus may also comprise a processor communicatively coupled to the transceiver. The processor, during operation, may perform operations comprising configuring one or more RSs to form an irregular RS pattern. The processor may also perform operations comprising transmitting, via the transceiver, a configuration of the one or more RSs to the receiver apparatus, wherein the configuration indicates time and frequency information related to the irregular RS pattern. The processor may further perform operations comprising transmitting, via the transceiver, the one or more RSs to the receiver apparatus based on the configuration for a sensing of a target object.

In one aspect, a method may involve a receiver apparatus receiving a configuration of one or more RSs from a transmitter apparatus, wherein the configuration indicates time and frequency information related to an irregular RS pattern of the one or more RSs. The method may also involve the receiver apparatus receiving the one or more RSs based on the configuration from the transmitter apparatus. The method may further involve the receiver apparatus performing a sensing of a target object according to the one or more RSs.

It is noteworthy that, although description provided herein may be in the context of certain radio access technologies (RATs) , networks and network topologies such as Long-Term Evolution (LTE) , LTE-Advanced, LTE-Advanced Pro, 5G, New Radio (NR) , Internet-of-Things (IoT) and Narrow Band Internet of Things (NB-IoT) , Industrial Internet of Things (IIoT) , beyond 5G (B5G) , and 6th Generation (6G) , the proposed concepts, schemes and any variation (s) /derivative (s) thereof may be implemented in, for and by other types of radio access technologies, networks and network topologies. Thus, the scope of the present disclosure is not limited to the examples described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of the present disclosure. The drawings illustrate implementations of the disclosure and, together with the description, serve to explain the principles of the disclosure. It is appreciable that the drawings are not necessarily in scale as some components may be shown to be out of proportion than the size in actual implementation in order to clearly illustrate the concept of the present disclosure.

FIG. 1 is a diagram depicting an example scenario of joint communication and sensing under schemes in accordance with the present disclosure.

FIG. 2 is a diagram depicting an example scenario of an irregular RS pattern under the first proposed scheme in accordance with the present disclosure.

FIGs. 3-5 are diagrams depicting example scenarios of an irregular RS pattern in case 1.1 under the first proposed scheme in accordance with the present disclosure.

FIG. 6 is a diagram depicting an example scenario of an irregular RS pattern in case 1.2 under the first proposed scheme in accordance with the present disclosure.

FIG. 7 is a diagram depicting an example scenario of an irregular RS pattern in case 1.3 under the first proposed scheme in accordance with the present disclosure.

FIG. 8 is a diagram depicting an example scenario of an irregular RS pattern in case 1.4 under the first proposed scheme in accordance with the present disclosure.

FIG. 9 is a diagram depicting an example scenario of an irregular RS pattern under the second proposed scheme in accordance with the present disclosure.

FIGs. 10-11 are diagrams example scenarios of an irregular RS pattern in case 2.1 under the second proposed scheme in accordance with the present disclosure.

FIG. 12 is a diagram depicting an example scenario of an irregular RS pattern in case 2.2 under the second proposed scheme in accordance with the present disclosure.

FIG. 13 is a block diagram of an example communication system in accordance with an implementation of the present disclosure.

FIG. 14 is a flowchart of an example process in accordance with an implementation of the present disclosure.

FIG. 15 is a flowchart of another example process in accordance with an implementation of the present disclosure.

DETAILED DESCRIPTION OF PREFERRED IMPLEMENTATIONS

Detailed embodiments and implementations of the claimed subject matters are disclosed herein. However, it shall be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matters which may be embodied in various forms. The present disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that description of the present disclosure is thorough and complete and will fully convey the scope of the present disclosure to those skilled in the art. In the description below, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

Overview

Implementations in accordance with the present disclosure relate to various techniques, methods, schemes and/or solutions pertaining to irregular RS pattern designs in joint communication and sensing. According to the present disclosure, a number of possible solutions may be implemented separately or jointly. That is, although these possible solutions may be described below separately, two or more of these possible solutions may be implemented in one combination or another.

When applying orthogonal frequency-division multiplexing (OFDM) to joint communication and sensing, RS configuration is vital in sensing performance, especially for passive sensing. With different RS patterns and different sensing algorithms, the ambiguity properties in the domains of propagation delay (i.e., distance) and Doppler frequency (i.e., velocity) may be different. Nonetheless, traditional solutions to distance and velocity detection in radar sensing do not consider communication system RS patterns and adapting their configuration parameters for desired distance-velocity ambiguity performance. Therefore, before completely new design of air interface becomes reality, how to provide superior ambiguity performance via different RS pattern designs in existing cellular systems remains an important issue.

In view of the above, the present disclosure aims to solve the problem of how to optimally utilize various RS patterns and sensing algorithms in existing cellular (e.g., 4G LTE or 5G NR) or future cellular (e.g., B5G or 6G) air interface. Specifically, the present disclosure provides methodologies of designing irregular RS patterns for super-resolution sensing algorithms, such as iterative adaptive approach (IAA) and two-dimension (2D) multiple signal classification (MUSIC) , to improve the ambiguity function characteristics and performance for sensing.

FIG. 1 illustrates an example scenario 100 of joint communication and sensing under schemes in accordance with the present disclosure. Scenario 100 involves a mobile communication system including a transmitter 110, a receiver 120, and one or more target objects 130～150, wherein the transmitter 110 and the receiver 120 supports irregular RS patterns for sensing any of the target objects 130～150. Each of the transmitter 110 and the receiver 120 may function as a user equipment (UE) or a base station (BS) . In one example, the transmitter 110 may be a BS and the receiver 120 may be a UE, or the transmitter 110 may be a UE and the receiver 120 may be a BS. In another example, the transmitter 110 and the receiver 120 may be two BSs or two UEs. The UE may include a smartphone, a smartwatch, a personal digital assistant, a digital camera, a tablet computer, a laptop computer, a notebook computer, or an IoT/NB-IoT/IIoT apparatus. The BS may include an evolved NodeB (eNB) in 4G LTE, or a next-generation NB (gNB) or a transmission and reception point (TRP) in 5G NR. Particularly, the transmitter 110 may configure one or more RSs as sensing RS (s) to form an irregular RS pattern, and transmit the sensing RS (s) . When reaching any of the target objects 130～150, the sensing RS (s) may be reflected towards the receiver 120, such that the receiver 120 may receive (and combine) the reflected sensing RS (s) (or called component RS (s) ) to perform sensing (e.g., estimating the distance and/or velocity) of the target object 130/140/150.

Under a first proposed scheme in accordance with the present disclosure, existing 5G RSs, such as comb RSs and phase tracking reference signal (PTRS) -like RSs, may be combined and configured to form an irregular RS pattern to mitigate all aliasing within the detectable 2D range (i.e., within the time delay domain and Doppler frequency shift domain) . Comb RSs may include physical downlink control channel (PDCCH) demodulation reference signal (DMRS) , physical downlink shared channel (PDSCH) DMRS Type-1/Type-2, channel state information-reference signal (CSI-RS) (Row 1 through Row 18) , tracking reference signal (TRS) , and positioning reference signal (PRS) . PTRS-like RSs may include PTRS and other RSs that share similar signal properties (e.g., low density in frequency domain and high density in time domain) with PTRS.

In some implementations, a sensing receiver (e.g., the receiver 120) may report its capability indication that combining the comb RS and the PRTS for sensing is supported to the sensing transmitter (e.g., the transmitter 110) , so that the sensing transmitter may determine to adopt the irregular RS pattern designs of the first proposed scheme.

FIG. 2 illustrates an example scenario 200 of an irregular RS pattern under the first proposed scheme in accordance with the present disclosure. Scenario 200 involves a plurality of parameters used to configure an irregular RS pattern, wherein the parameters include S_sub, S_sym, F_i, K, M, C₁, C₂, S_F, S_PT, U_F, U, T_s, T_cp, and T. S_sub (unit in subcarrier numbers) denotes the spacing of the comb RS resource elements (REs) in frequency domain, and S_sub≥2 for comb structure (i.e., S_sub=4 in FIG. 2) . S_sym (unit in symbol numbers) denotes the spacing of the comb RS symbols in time domain (i.e., S_sym=3 in FIG. 2) . F_i (unit in subcarrier numbers) denotes the staggering offset in the frequency domain of the i-th comb RS symbol. K denotes the number of REs in the frequency domain for one comb RS symbol in one snapshot (i.e., K=3 in FIG. 2) . M denotes the number of RS symbols in one snapshot (i.e., M=4 in FIG. 2) . C₁ (unit in subcarrier numbers) denotes the RE offset of PTRS-like patterns (i.e., C₁=6 in FIG. 2) . C₂ (unit in symbol numbers) denotes the location in the time domain of the first PTRS-like symbol (i.e., C₂=1 in FIG. 2) . S_F (unit in subcarrier numbers) denotes the spacing of the PTRS-like REs in frequency domain. S_PT (unit in symbol numbers) denotes the spacing of the PTRS-like symbols in time. U_F denotes the number of REs in the frequency domain for one PTRS-like symbol in one snapshot (i.e., U_F=2 in FIG. 2) . U denotes the number of PTRS-like symbols in one snapshot (i.e., M=3 in FIG. 2) . T_s denotes the OFDM duration. T_cp denotes the cyclic prefix (CP) duration. T=T_cp+T_s denotes the CP-added OFDM symbol duration. Generally speaking, these parameters may be used to indicate time and frequency information related to the irregular RS patter, and they can be provided in a configuration through, e.g., sensing control by radio resource control (RRC) messages, or medium access control (MAC) control element (CE) enable/disable, or physical layer control indication, or any combination thereof. For example, the configuration may include an indication of a set of values pre-defined for these parameters (e.g., pre-defined by look-up table (s) in 3GPP specifications) .

With above parameters, the h_th column of the steering matrix (formed by 2D MUSIC or IAA) may be written as:

where f_h and τ_h are the Doppler frequency and time delay of the h-th target and W_h1 can be represented as follows:

If W_h2 is empty, the W_h1 cannot be distinguished between (τ, f) and for integer pair (k₁, k₂) , regardless of the choices of staggering offset F_i. Now, after combining with W_h2, this scheme may guarantee that there is no aliasing (or side peaks with equal power to the mainlobe) between (τ, f) andfor integer pair (k₁, k₂) , which extended the Doppler ambiguity range.

Consider the case that the vector W_h2 is non-empty. If the vector W_h1 is empty, W_h2 is equivalent to non-staggered patterns which cannot eliminate all side peaks. Hence, here we focus on the case of M≥1. At this moment, it is assumed that F₀=0 without loss of generality. It is noted that the phase rotation will be applied back and the general case will be addressed later. In such a situation, the pair (τ, f) cannot be distinguished from the pair (τ′, f′) using the information from W_h2 if the following condition hold true:

Next, the parameters configuration of the first proposed scheme further breaks down into 4 cases as follows.

Case 1.1: with M≥2 (Resolving ambiguities by RE insertion between at least 2 Freq-Comb staggering RS symbols)

In order to make (τ, f) indistinguishable from the pair (τ′, f′) , we need and κ₂: =S_symS_subT (f′-f) to be both integers, and the ambiguity about the vector W_h1 has been shown to be equivalent to the following anti-condition.
mod (l κ₂- (F_l-F₀) κ₁, S_sub) =0, for l=1, 2, …, M-1. (2)

By substituting the expressions of κ₁ and κ₂ into equation (1) , an additional anti-condition can be derived as follows.
mod ( (C₂+l S_PT) κ₂- (C₁+iS_F) S_symκ₁, S_symS_sub) =0,

for any l=0, 1, …, U-1, , i=0, 1, .., U_F-1 (3)

Above derivations are based on the assumption F₀=0. In general, one may replace C₁ with C₁-F₀, and F_l with F_l-F₀ for each l, and obtain the following anti-condition.
mod ( (C₂+l S_PT) κ₂- (C₁+iS_F-F₀) S_symκ₁, S_symS_sub) =0,

for any l=0, 1, …, U-1, , i=0, 1, .., U_F-1 (4)

Note that with the help of the vector W_H, ₂, we can ensure the non-existence of side peaks within the range τ′-τ∈ (0, T_s) andIn doing that, we need to guarantee the non-existence of a non-zero integer solution (κ₁, κ₂) ∈ {0, 1, 2, …, S_sub-1} × {0, 1, …, S_symS_sub-1} to the system of equations formed by the two anti-condition equations (2) and (4) .

The anti-condition equation (4) can be simplified under different situations. For example, if U≥2 and U_F≥2, equation (4) is equivalent to the following set of conditions: mod (S_PTκ₂, S_symS_sub) =0, mod (S_Fκ₁, S_sub) =0, mod (C₂κ₂- (C₁-F₀) κ₁, S_symS_sub) =0. If U≥2 and U_F=1, equation (4) is equivalent to the following set of conditions: mod (S_PTκ₂, S_symS_sub) =0, mod (C₂κ₂- (C₁-F₀) κ₁, S_symS_sub) =0. If U=1 and U_F≥2, equation (4) is equivalent to the following set of conditions: mod (S_Fκ₁, S_sub) =0, mod (C₂κ₂- (C₁-F₀) κ₁, S_symS_sub) =0.

Subsequently, some examples are provided such that the solution to the anti-condition does not exist. Consider the case of M=2, with F₀=0 and F₁=1. One way of ensuring the nonexistence of the solution is by taking U≥1, and choosing the pair (C₁, C₂) such that C₂+l^*S_PT- (C₁+i^*S_F-F₀) S_sym and S_sub are relative prime for some l^*∈ {0, 1, …, U-1} and , i^*∈ {0, 1, …, U_F-1} . In such case, first anti-condition equation (2) implies that κ₂-κ₁ is an integer multiple of S_sub, which implies that:
mod ( (C₁+iS_F-F₀) S_sym (κ₁-κ₂) , S_symS_sub) =0 (5)

Substituting the above equation into the anti-condition equation (4) , we have that:
mod ( (C₂+l S_PT- (C₁+i S_F-F₀) S_sym) κ₂, S_symS_sub) =0 (6)

Since C₂+l^*S_PT- (C₁+i^*S_F-F₀) S_sym and S_symS_sub are relative prime for some l^*∈ {0, 1, …, U-1} and i^*∈ {0, 1, …, U_F-1} , the anti-condition at the pair (l^*, i^*) requires κ₂ to be an integer multiple of S_symS_sub, which implies that κ₁ is an integer multiple of S_sub. Since we have κ₁∈ {0, 1, …, S_sub-1} and κ₂∈ {0, 1, …, S_symS_sub-1} , the only possibility is κ₁=κ₂=0. Therefore, under this setup, when we have U≥1 and C₂+l^*S_PT- (C₁+i^*S_F-F₀) S_sym and S_symS_sub are relative prime for some l^*∈ {0, 1, …, U-1} and i^*∈ {0, 1, …, U_F-1} , the ambiguity due to aliasing does not exist in the desired range.

FIGs. 3-5 illustrate example scenarios 300, 400, and 500 of an irregular RS pattern in case 1.1 under the first proposed scheme in accordance with the present disclosure. As shown in FIG. 3, the left part depicts the irregular RS pattern configured with the parameters: M=2, F₀=0 and F₁=1, S_sub=6, C₁=1, C₂=3, S_sym=4, U=1, U_F=1, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true time delay and Doppler frequency shift pair with respect to the corresponding parameters. As shown in FIG. 4, the left figure depicts the irregular RS pattern configured with the parameters: M=2, F₀=0 and F₁=1, S_sub=8, C₁=1, C₂=2, S_sym=3, U=1, U_F=1, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true delay and Doppler pair with respect to the corresponding parameters. As shown in FIG. 5, the left figure depicts the irregular RS pattern configured with the parameters: M=2, F₀=0 and F₁=1, S_sub=4, C₁=1, C₂=3, S_sym=10,U=1, U_F=3, S_F=3, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true delay and Doppler pair with respect to the corresponding parameters. It is noteworthy that, in the right figures of FIGs. 3-5, side peaks within the desired range are eliminated.

Case 1.2: with M=1, U≥2 and U_F=1 (Resolving ambiguities by combining PTRS with single-tone Freq-Comb RS)

Comparing the cases (i=0, l=0) and (i=0, l=1) for the anti-condition equation (1) implies that the quantity κ₃=S_PTT (f′-f) is an integer in {0, 1, …, S_PT-1} . Additionally, the indistinguishability of the vector W_h1 in the l=0 case implies that is an integer in {0, 1, …, S_sub-1} . Furthermore, applying the anti-condition equation (1) with (i=0, l=0) implies thatis an integer. On the other hand, ifare all integers, we have that is an integer, and the anti-condition equation (1) will hold for any l≥0. Therefore, in order to ensure the non-existence of ambiguous side peaks in the range τ′-τ∈ (0, T_s) , the necessary and sufficient condition is the non-existence of a non-zero integer solution (κ₁, κ₃) ∈ [0, S_sub-1] × [0, S_PT-1] to the following anti-condition:

wheredenotes arbitrary integers.

Above derivations are based on the assumption F₀=0. In general, one may replace C₁ with C₁-F₀, and F_l with F_l-F₀ for each l, and obtain the following anti-condition:

To look into this condition in more detail, firstly, note that the pair and (τ, f) make the anti-condition hold true, where gcd () is the greatest common divisor. In order to ensure that no solution exists for τ′-τ∈ (0, T_s) , we need C₁ and S_sub to be relative prime. On the other hand, note that the pairand (τ, f) make the anti-condition hold true. In order to ensure that no solution exists for f′-f∈ (0, 1/T ) , we need C₂ and S_PT to be relative prime. These two conditions are necessary but not sufficient.

On the other hand, examples can be constructed for which the condition hold. Suppose that the system is designed such that gcd (S_PT, S_sub) =1 so that they are relative prime. The quantitybeing an integer implies that both terms are integers. As long as we ensure that C₁ and S_sub are relative prime and C₂ and S_PT are relative prime, the non-existence of the solution to the anti-condition equation (8) can be ensured.

FIG. 6 illustrate an example scenario 600 of an irregular RS pattern in case 1.2 under the first proposed scheme in accordance with the present disclosure. As shown in FIG. 6, the left figure depicts the irregular RS pattern configured with the parameters: M=1, F₀=0, S_sub=2, C₁=1, C₂=1, U=3, U_F=1, S_PT=1, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true delay and Doppler pair with respect to the corresponding parameters. It is noteworthy that, in the right figure of FIG. 6, side peaks within the desired range are eliminated.

Case 1.3: with M=1, U≥2 and U_F≥2 (Resolving ambiguities by combining PTRS with single-tone Freq-Comb RS)

Similar to case 1.2, the existence of ambiguous side peaks implies that κ₃=S_PTT (f′-f) is an integer in {0, 1, …, S_PT-1} , is an integer in {0, 1, …, S_sub-1} , and thatis an integer. Furthermore, comparing the cases (i=1, l=0) and (i=0, l=0) for the anti-condition equation (1) , we obtain that is an integer. On the other hand, ifare all integers, we have that:

and the anti-condition equation (1) will hold for any l≥0 and i≥0.

Therefore, in order to ensure the non-existence of ambiguous side peaks in the range τ′-τ∈ (0, T_s) , the necessary and sufficient condition is the non-existence of a non-zero integer solution (κ₁, κ₃) ∈ [0, S_sub-1] × [0, S_PT-1] to the following anti-condition:

FIG. 7 illustrate an example scenario 700 of an irregular RS pattern in case 1.3 under the first proposed scheme in accordance with the present disclosure. As shown in FIG. 7, the left figure depicts the irregular RS pattern configured with the parameters: M=1, F₀=0, S_sub=5, C₁=1, C₂=1, U=3, U_F=2, S_PT=3, S_F=3, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true delay and Doppler pair with respect to the corresponding parameters. It is noteworthy that, in the right figure of FIG. 7, side peaks within the desired range are eliminated.

Case 1.4: with M=1, U1=1 (Resolving ambiguities by combining single-tone PTRS with single-tone Freq-Comb RS)

In this case, we need U_F≥2 to eliminate ambiguities. The indistinguishability of the vector W_h1 in the l=0 case implies thatis an integer in {0, 1, …, S_sub-1} . Comparing the cases (i=1, l=0) and (i=0, l=0) for the anti-condition equation (1) , we obtain thatis an integer. Furthermore, applying the anti-condition equation (1) with (i=0, l=0) implies thatis an integer. Therefore, we have κ₄:=C₂S_subT (f′-f) is an integer. In such case, the necessary and sufficient condition for the non-existence of ambiguous side peaks is the non-existence of a non-zero integer solution (κ₁, κ₄) ∈ [0, S_sub-1] × [0, C₂S_sub-1] to the following anti-condition:

where mod () is modulo operation.

Note that if C₂>1, such an anti-condition is always satisfied by (κ₁=0, κ₄=S_sub) . Therefore, for the non-existence of the solution to hold, we need C₂=1. Taking into account the constant phase rotation caused by F₀, in order to ensure the non-existence of ambiguous side peaks in the range τ′-τ∈ (0, T_s) , the necessary and sufficient condition is the non-existence of a non-zero integer solution (κ₁, κ₃) ∈ [0, S_sub-1] × [0, S_PT-1] to the following anti-condition:

FIG. 8 illustrate an example scenario 800 of an irregular RS pattern in case 1.4 under the first proposed scheme in accordance with the present disclosure. As shown in FIG. 8, the left figure depicts the irregular RS pattern configured with the parameters: M=1, F₀=0, S_sub=5, C₁=1, C₂=1, U=1, U_F=4, S_F=3, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true delay and Doppler pair with respect to the corresponding parameters. It is noteworthy that, in the right figure of FIG. 8, side peaks within the desired range are eliminated.

Under a second proposed scheme in accordance with the present disclosure, a more general irregular RS pattern (or called a generalized irregular RS pattern) may be used which indicates that resource elements (REs) of the RS (s) are not uniformly spaced either in each RS symbol or across RS symbols.

In some implementations, a sensing receiver (e.g., the receiver 120) may report its capability indication that the generalized irregular RS pattern for sensing is supported to the sensing transmitter (e.g., the transmitter 110) , so that the sensing transmitter may determine to adopt the irregular RS pattern designs of the second proposed scheme.

FIG. 9 illustrates an example scenario 900 of an irregular RS pattern under the second proposed scheme in accordance with the present disclosure. Scenario 900 depicts the case of at least one RS symbol has two or more REs, which involves a plurality of parameters used to configure a generalized irregular RS pattern. The parameters include d_g, j, K_g, S_g, and G. d_g, j denotes the RE offset of the jth RE at the gth RS symbol. K_g denotes the total number of RS REs at the gth RS symbol. S_g denotes the RS symbol index of the gth RS symbol. G denotes the total number of RS symbols. WLOG: d_1, 1=0 and S₁=0 are shown in the plot. A pair of parameters (τ, f) results in ambiguity with another pair (τ′, f′) , iffor any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} . In this case, such thatTake an arbitrary index pair (k^*, l^*) ∈ {1, …, K_g} × {1, …, K_g} , where k^*≠l^*. And define (minimal same-symbol RE distance found in multi-RE symbols) , and S^*=gcd (S₂-S₁, …, S_G-S₁) , where gcd is the greatest common divisor between symbol time offsets. The anti-condition for ambiguity is: there exists no non-zero integer pair (κ₁, κ₂) ∈ {0, 1, …, d^*-1} × {0, 1, …, S^*d^*-1} such that mod ( (S_g-S₁) κ₂- (d_g, _k-d_1, ₁) S^*κ₁, S^*d^*) =0, for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} .

With above parameters, the h_th column of the steering matrix w_h (formed by 2D MUSIC or IAA) of the generalized irregular RS patter is shown below.

In the steering matrix, d_gj denotes the RE offset of the j-th RE along the frequency domain in the g-th RS symbol, K_g denotes the number of REs in the frequency domain of the g-th RS symbol, S_g denotes the symbol index of the g-th RS symbol, and G denotes the total number of RS symbols in one snapshot. Note that d_ij and S_g are not necessarily uniform spaced, which could form an irregular pattern. Generally speaking, these parameters may be used to indicate time and frequency information related to the irregular RS patter, and they can be provided in a configuration through, e.g., sensing control by RRC messages, or MAC CE enable/disable, or physical layer control indication, or any combination thereof. For example, the configuration may include an indication of a set of values pre-defined for these parameters (e.g., pre-defined by look-up table (s) in 3GPP specifications) .

Due to invariance to constant phase rotation, it is assumed d₁₁=S₁=0 without loss of generality. A pair of ambiguous objects (τ, f) and (τ′, f′) satisfies that:

for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} (14)

Next, the parameters configuration of the second proposed scheme further breaks down into 2 cases as follows.

Case 2.1: there exists a g^*∈ {1, 2, …, G} , such that (Two or more REs for at least one RS symbol)

Take an arbitrary distinct pairand define (The choice of g^*, k^*and l^*does not affect the conclusion, as different choices all lead to equivalent conditions. For the sake of computational simplicity, one may choose Applying equation (14) with (g^*, k^*) and (g^*, l^*) and taking their difference, we have thatIf an ambiguity exists in the range τ′-τ∈ [0, T_s) , we have that κ₁∈ {0, 1, 2, …, d^*-1} . Then, substituting into equation (14) , we have that:

for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} (15)

Consequently, for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} , we have Since we have assumed S₁=0, we need G≥2 and S₂≠0 for this constraint to be effective. Let S^*:⁼gcd (S₂-S₁, …, S_G-S₁) , where gcd denotes the greatest common divisor. We have κ₂:=S^*d^*T (f′-f) ∈Z. Ifwe have κ₂∈ {0, 1, 2, …, S^*d^*-1} . Under such a representation, the anti-condition equation (14) becomes:
mod (S_gκ₂-d_gkS^*κ₁, S^*d^*) =0,

for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} (16)

Above derivations are based on the assumption S₁=d₁₁=0. In general, one may replace S_g with S_g-S₁, and d_gk with d_gk-d₁₁, and obtain the following anti-condition:
mod ( (S_g-S₁) κ₂- (d_gk-d₁₁) S^*κ₁, S^*d^*) =0,

for any g∈ {1, 2, …, G} and k∈ {1, 2, …, K_g} (17)

Therefore, the distinguishability in the desirable range is equivalent to the non-existence of a non-zero solution κ₁∈ {0, 1, …, d^*-1} , κ₂∈ {0, 1, …, S^*d^*-1} to the anti-condition equation (17) .

In this case, we need G≥2, with at least one RS symbol satisfying K_g≥2. At least 3 entries are need for the vector W_h.

FIGs. 10-11 illustrate example scenarios 1000 and 1100 of an irregular RS pattern in case 2.1 under the second proposed scheme in accordance with the present disclosure. As shown in FIG. 10, the left part depicts the irregular RS pattern configured with the parameters: G=3, d₁₁=1, d₁₂=2, d₁₃=12, d₁₄=13, d₂₁=1, d₂₂=10, d₂₃=11, d₃₁=7, d₃₂=10, S₁=0, S₂=3, S₃=7, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true time delay and Doppler frequency shift pair with respect to the corresponding parameters. As shown in FIG. 11, the left figure depicts the irregular RS pattern configured with the parameters: G=2, d₁₁=1, d₁₂=2, d₁₃=9, d₁₄=13, d₂₁=1, d₂₂=7, d₂₃=11, S₁=0, S₂=1, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true time delay and Doppler frequency shift pair with respect to the corresponding parameters. It is noteworthy that, in the right figures of FIGs. 10-11, side peaks within the desired range are eliminated.

Case 2.2: for any g∈ {1, 2, …, G} , there is K_g=1 (Single RE for every RS symbol)

For notation simplicity, we use d_g to denote d_g1 for any g∈ {1, 2, …, G} . As before, we let d₁=S₁=0 to deal with rotation invariance. In such case, we need the existence of a pair of integers m, n≥2, such that (The choice of (m, n) pair does not affect the conclusion, as different choices all lead to equivalent conditions) . Suppose that such a pair does not exist, it is easy to see that (d_g-d₁, S_g-S₁) are all integer multiples of an integer pairAny (τ, f) pair satisfyingwill lead to ambiguity, which does not satisfy our requirements. Therefore, we need the existence of such (m, n) . Applying equation (14) with (m, 1) and (n, 1) respectively and combining them together, we have:

Define S^**:=| (d_m-d₁) (S_n-S₁) - (S_m-S₁) (d_n-d₁) |>0. We therefore haveIf an ambiguity exists in the range τ′-τ∈ [0, T_s) , we have that κ₁∈ {0, 1, 2, …, S^**-1} .

On the other hand, another linear combination of equation (14) with (g₁, 1) and (g₂, 1) yields:

which implies the fact thatIf an ambiguity exists in the range we have that κ₂∈ {0, 1, 2, …, S^*-1} . Substituting the expressions of (κ₁, κ₂) to Eq (12) , we obtain an equivalent expression:
mod ( (S_g-S₁) κ₂- (d_g-d₁) κ₁, S^**) =0,

for any g∈ {1, 2, …, G} (20)

Therefore, the distinguishability in the desirable range τ′-τ∈ (0, T_s) , is equivalent to the non-existence of a non-zero solution κ₁∈ {0, 1, …, S^**-1} , κ₂∈ {0, 1, …, S^**-1} to equation (20) .

In this case, we need a distinct pair m, n∈ {2, 3, …, G} . Therefore, we have G≥3, and at least 3 entries are needed in the vector W_h.

FIG. 12 illustrates an example scenario 1200 of an irregular RS pattern in case 2.2 under the second proposed scheme in accordance with the present disclosure. As shown in FIG. 12, the left part depicts the irregular RS pattern configured with the parameters: G=11, d₁₁=0, d₂₁=1, d₃₁=3, d₄₁=9, d₅₁=13, d₆₁=5, d₇₁=7, d₈₁=8, d₉₁=2, d₁₀₁=1, d₁₁₁=0, S_g=g-1 for g=1, 2, 3, …11, while the right figure depicts the ambiguity performance of 2D MUSIC or IAA with (0, 0) as the true time delay and Doppler frequency shift pair with respect to the corresponding parameters. It is noteworthy that, in the right figure of FIG. 12, side peaks due to aliasing within the desired range are eliminated.

Note that the above derivations and equations only guarantee there are no side peaks due to aliasing (i.e., side peaks with equal power to mainlobe) in the range τ′-τ∈ (0, T_s) , There might be some side peaks with lower power than mainlobe in some cases (e.g., RE number is small, comb density is sparse) . To guarantee the best ambiguity performance, one needs to choose an RS pattern with side peaks having the lowest power from a set of patterns derived from the aforementioned anti-conditions.

Illustrative Implementations

FIG. 13 illustrates an example communication system 1300 having two example communication apparatus 1310 and 1320 in accordance with an implementation of the present disclosure. Each of communication apparatus 1310 and communication apparatus 1320 may perform various functions to implement schemes, techniques, processes and methods described herein pertaining to irregular RS pattern designs in joint communication and sensing, including scenarios/schemes described above as well as processes 1400 and 1500 described below.

Each of communication apparatus 1310 and communication apparatus 1320 may be a part of an electronic apparatus, which may be a UE such as a portable or mobile apparatus, a wearable apparatus, a wireless communication apparatus or a computing apparatus (e.g., mounted on vehicles) . For instance, communication apparatus 1310/1320 may be implemented in a smartphone, a smartwatch, a personal digital assistant, a digital camera, or a computing equipment such as a tablet computer, a laptop computer or a notebook computer. Each of communication apparatus 1310 and communication apparatus 1320 may also be a part of a machine type apparatus, which may be an IoT, NB-IoT, or IIoT apparatus such as an immobile or a stationary apparatus, a home apparatus, a wire communication apparatus or a computing apparatus. For instance, communication apparatus 1310/1320 may be implemented in a smart thermostat, a smart fridge, a smart door lock, a wireless speaker or a home control center. Alternatively, each of communication apparatus 1310 and communication apparatus 1320 may be a part of an electronic apparatus, which may be a network node such as a BS, a small cell, a router or a gateway. For instance, communication apparatus 1310/1320 may be implemented in an eNodeB in an LTE, LTE-Advanced or LTE-Advanced Pro network or in a gNB in a 5G, NR, IoT, NB-IoT or IIoT network. Furthermore, each of communication apparatus 1310 and communication apparatus 1320 may be implemented in the form of one or more integrated-circuit (IC) chips such as, for example and without limitation, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction set computing (RISC) processors, or one or more complex-instruction-set-computing (CISC) processors. Communication apparatus 1310/1320 may include at least some of those components shown in FIG. 12 such as a processor 1312/1322, for example. Communication apparatus 1310/1320 may further include one or more other components not pertinent to the proposed scheme of the present disclosure (e.g., internal power supply, display device and/or user interface device) , and, thus, such component (s) of communication apparatus 1310/1320 are neither shown in FIG. 13 nor described below in the interest of simplicity and brevity.

In one aspect, each of processor 1312 and processor 1322 may be implemented in the form of one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, even though a singular term “a processor” is used herein to refer to processor 1312 and processor 1322, each of processor 1312 and processor 1322 may include multiple processors in some implementations and a single processor in other implementations in accordance with the present disclosure. In another aspect, each of processor 1312 and processor 1322 may be implemented in the form of hardware (and, optionally, firmware) with electronic components including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors and/or one or more varactors that are configured and arranged to achieve specific purposes in accordance with the present disclosure. In other words, in at least some implementations, each of processor 1312 and processor 1322 is a special-purpose machine specifically designed, arranged and configured to perform specific tasks including irregular RS pattern designs in joint communication and sensing in accordance with various implementations of the present disclosure.

In some implementations, communication apparatus 1310 may also include a transceiver 1316 coupled to processor 1312 and capable of wirelessly transmitting and receiving RSs and data signals. In some implementations, transceiver 1316 may be capable of wirelessly communicating with different types of UEs/BSs of different RATs. In some implementations, transceiver 1316 may be equipped with a plurality of antenna ports (not shown) such as, for example, four antenna ports. That is, transceiver 1316 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input multiple-output (MIMO) wireless communications. In some implementations, communication apparatus 1320 may also include a transceiver 1326 coupled to processor 1322 and capable of wirelessly transmitting and receiving RSs and data signals. In some implementations, transceiver 1326 may be capable of wirelessly communicating with different types of UEs/BSs of different RATs. In some implementations, transceiver 1326 may be equipped with a plurality of antenna ports (not shown) such as, for example, four antenna ports. That is, transceiver 1326 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communications. Accordingly, communication apparatus 1310 and communication apparatus 1320 may wirelessly communicate with each other directly or indirectly (e.g., by reflection from any object therebetween) via transceiver 1316 and transceiver 1326, respectively.

In some implementations, communication apparatus 1310 may further include a memory 1314 coupled to processor 1312 and capable of being accessed by processor 1312 and storing data therein. In some implementations, communication apparatus 1320 may further include a memory 1324 coupled to processor 1322 and capable of being accessed by processor 1322 and storing data therein. Each of memory 1314 and memory 1324 may include a type of random-access memory (RAM) such as dynamic RAM (DRAM) , static RAM (SRAM) , thyristor RAM (T-RAM) and/or zero-capacitor RAM (Z-RAM) . Alternatively, or additionally, each of memory 1314 and memory 1324 may include a type of read-only memory (ROM) such as mask ROM, programmable ROM (PROM) , erasable programmable ROM (EPROM) and/or electrically erasable programmable ROM (EEPROM) . Alternatively, or additionally, each of memory 1314 and memory 1324 may include a type of non-volatile random-access memory (NVRAM) such as flash memory, solid-state memory, ferroelectric RAM (FeRAM) , magnetoresistive RAM (MRAM) and/or phase-change memory.

Each of communication apparatus 1310 and communication apparatus 1320 may be a communication entity capable of communicating with each other using various proposed schemes in accordance with the present disclosure. For illustrative purposes and without limitation, a description of operations, functionalities, and capabilities of communication apparatus 1310, implemented in or as a sensing RS transmitter (e.g., a UE or a BS) , and communication apparatus 1320, implemented in or as a sensing RS receiver (e.g., a UE or a BS) , is provided below.

According to certain proposed schemes of the present disclosure, processor 1312 of communication apparatus 1310 may configure one or more RSs to form an irregular RS pattern. Then, processor 1312 may transmit, via transceiver 1316, a configuration of the one or more RSs to communication apparatus 1320, wherein the configuration indicates time and frequency information related to the irregular RS pattern. Also, processor 1312 may transmit, via transceiver 1316, the one or more RSs to communication apparatus 1320 based on the configuration for a sensing of a target object.

In some implementations, the one or more RSs may include a comb RS and a PTRS-like RS.

In some implementations, the comb RS may include one of the following: a DMRS, a CSI-RS, a TRS, and a PRS.

In some implementations, processor 1312 may also receive, via transceiver 1316, an indication that combining the comb RS and the PRTS for sensing is supported from communication apparatus 1320.

In some implementations, the irregular RS pattern may be a generalized irregular RS pattern indicating that REs of the one or more RSs are not uniformly spaced either in each RS symbol or across RS symbols.

In some implementations, processor 1312 may also receive, via transceiver 1316, an indication that the generalized irregular RS pattern for sensing is supported from communication apparatus 1320.

In some implementations, the sensing may include at least one of a distance estimation and a velocity estimation of the target object. For example, time delay can be used to calculate/estimate the distance of the target object and Doppler frequency shift can be used to calculate/estimate the velocity of the target object, given a certain carrier frequency.

According to certain proposed schemes of the present disclosure, processor 1322 of communication apparatus 1320 may receive, via transceiver 1326, a configuration of one or more RSs from communication apparatus 1310, wherein the configuration indicates time and frequency information related to an irregular RS pattern of the one or more RSs. Then, processor 1322 may receive, via transceiver 1326, the one or more RSs based on the configuration from communication apparatus 1310. Also, processor 1322 may perform a sensing of a target object according to the one or more RSs.

In some implementations, processor 1322 may also transmit, via transceiver 1326, an indication that combining the comb RS and the PRTS for sensing is supported to communication apparatus 1310.

In some implementations, processor 1322 may also transmit, via transceiver 1326, an indication that the generalized irregular RS pattern for sensing is supported to communication apparatus 1310.

In some implementations, the sensing may include at least one of a distance estimation and a velocity estimation of the target object.

Illustrative Processes

FIG. 14 illustrates an example process 1400 in accordance with an implementation of the present disclosure. Process 1400 may be an example implementation of above scenarios/schemes, whether partially or completely, with respect to irregular RS pattern designs in joint communication and sensing. Process 1400 may represent an aspect of implementation of features of communication apparatus 1310. Process 1400 may include one or more operations, actions, or functions as illustrated by one or more of blocks 1410 to 1430. Although illustrated as discrete blocks, various blocks of process 1400 may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks of process 1400 may be executed in the order shown in FIG. 14 or, alternatively, in a different order. Process 1400 may be implemented by communication apparatus 1310 or any suitable UE or BS. Solely for illustrative purposes and without limitation, process 1400 is described below in the context of communication apparatus 1310 as a sensing RS transmitter and communication apparatus 1320 as a sensing RS receiver. Process 1400 may begin at block 1410.

At 1410, process 1400 may involve processor 1312 of communication apparatus 1310 configuring one or more RSs to form an irregular RS pattern. Process 1400 may proceed from 1410 to 1420.

At 1420, process 1400 may involve processor 1312 transmitting, via transceiver 1316, a configuration of the one or more RSs to communication apparatus 1320, wherein the configuration indicates time and frequency information related to the irregular RS pattern. Process 1400 may proceed from 1420 to 1430.

At 1430, process 1400 may involve processor 1312 transmitting, via transceiver 1316, the one or more RSs to communication apparatus 1320 based on the configuration for a sensing of a target object.

In some implementations, process 1400 may further involve processor 1312 receiving, via transceiver 1316, an indication that combining the comb RS and the PRTS for sensing is supported from communication apparatus 1320.

In some implementations, process 1400 may further involve processor 1312 receiving, via transceiver 1316, an indication that the generalized irregular RS pattern for sensing is supported from communication apparatus 1320.

FIG. 15 illustrates an example process 1500 in accordance with an implementation of the present disclosure. Process 1500 may be an example implementation of above scenarios/schemes, whether partially or completely, with respect to irregular RS pattern designs in joint communication and sensing. Process 1500 may represent an aspect of implementation of features of communication apparatus 1320. Process 1500 may include one or more operations, actions, or functions as illustrated by one or more of blocks 1510 to 1530. Although illustrated as discrete blocks, various blocks of process 1500 may be divided into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Moreover, the blocks of process 1400 may be executed in the order shown in FIG. 15 or, alternatively, in a different order. Process 1500 may be implemented by communication apparatus 1320 or any suitable UE or BS. Solely for illustrative purposes and without limitation, process 1500 is described below in the context of communication apparatus 1320 as a sensing RS receiver and communication apparatus 1310 as a sensing RS transmitter. Process 1500 may begin at block 1510.

At 1510, process 1500 may involve processor 1322 of communication apparatus 1320 receiving, via transceiver 1326, a configuration of one or more RSs from communication apparatus 1310, wherein the configuration indicates time and frequency information related to an irregular RS pattern of the one or more RSs. Process 1500 may proceed from 1510 to 1520.

At 1520, process 1500 may involve processor 1322 receiving, via transceiver 1326, the one or more RSs based on the configuration from communication apparatus 1310. Process 1500 may proceed from 1520 to 1530.

At 1530, process 1500 may involve processor 1322 performing a sensing of a target object according to the one or more RSs.

In some implementations, process 1500 may further involve processor 1322 transmitting, via transceiver 1326, an indication that combining the comb RS and the PRTS for sensing is supported to communication apparatus 1310.

In some implementations, process 1500 may further involve processor 1322 transmitting, via transceiver 1326, an indication that the generalized irregular RS pattern for sensing is supported to communication apparatus 1310.

Additional Notes

The herein-described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being "operably connected" , or "operably coupled" , to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable" , to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

Further, with respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

Moreover, it will be understood by those skilled in the art that, in general, terms used herein, and especially in the appended claims, e.g., bodies of the appended claims, are generally intended as “open” terms, e.g., the term “including” should be interpreted as “including but not limited to, ” the term “having” should be interpreted as “having at least, ” the term “includes” should be interpreted as “includes but is not limited to, ” etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to implementations containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an, " e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more; ” the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, e.g., the bare recitation of "two recitations, " without other modifiers, means at least two recitations, or two or more recitations. Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc. ” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. In those instances where a convention analogous to “at least one of A, B, or C, etc. ” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B. ”

From the foregoing, it will be appreciated that various implementations of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various implementations disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

A method, further comprising:

configuring, by a processor of a transmitter apparatus, one or more reference signals (RSs) to form an irregular RS pattern;

transmitting, by the processor, a configuration of the one or more RSs to a receiver apparatus, wherein the configuration indicates time and frequency information related to the irregular RS pattern; and

transmitting, by the processor, the one or more RSs to the receiver apparatus based on the configuration for a sensing of a target object.
The method of Claim 1, wherein the one or more RSs comprise a comb RS and a phase tracking reference signal (PTRS) -like RS.
The method of Claim 2, wherein the comb RS comprises at least one of the following:

a demodulation reference signal (DMRS) ;

a channel state information-reference signal (CSI-RS) ;

a tracking reference signal (TRS) ; and

a positioning reference signal (PRS) .
The method of Claim 2, further comprising:

receiving, by the processor, an indication that combining the comb RS and the PRTS for sensing is supported from the receiver apparatus.
The method of Claim 1, wherein the irregular RS pattern is a generalized irregular RS pattern indicating that resource elements (REs) of the one or more RSs are not uniformly spaced either in each RS symbol or across RS symbols.
The method of Claim 5, further comprising:

receiving, by the processor, an indication that the generalized irregular RS pattern for sensing is supported from the receiver apparatus.
The method of Claim 1, wherein the sensing comprises at least one of a distance estimation and a velocity estimation of the target object.
A transmitter apparatus, comprising:

a transceiver which, during operation, wirelessly communicates with a receiver apparatus; and

a processor communicatively coupled to the transceiver such that, during operation, the processor performs operations comprising:

configuring one or more reference signals (RSs) to form an irregular RS pattern;

transmitting, via the transceiver, a configuration of the one or more RSs to the receiver apparatus, wherein the configuration indicates time and frequency information related to the irregular RS pattern; and

transmitting, via the transceiver, the one or more RSs to the receiver apparatus based on the configuration for a sensing of a target object.
The transmitter apparatus of Claim 8, wherein the one or more RSs comprise a comb RS and a phase tracking reference signal (PTRS) -like RS.
The transmitter apparatus of Claim 9, wherein the comb RS comprises at least one one of the following:

a demodulation reference signal (DMRS) ;

a channel state information-reference signal (CSI-RS) ;

a tracking reference signal (TRS) ; and

a positioning reference signal (PRS) .
The transmitter apparatus of Claim 9, wherein, during operation, the processor further performs operations comprising:

receiving, via the transceiver, an indication that combining the comb RS and the PRTS for sensing is supported from the receiver apparatus.
The transmitter apparatus of Claim 8, wherein the irregular RS pattern is a generalized irregular RS pattern indicating that resource elements (REs) of the one or more RSs are not uniformly spaced either in each RS symbol or across RS symbols.
The transmitter apparatus of Claim 12, wherein, during operation, the processor further performs operations comprising:

receiving, via the transceiver, an indication that the generalized irregular RS pattern for sensing is supported from the receiver apparatus.
A method, comprising:

receiving, by a processor of a receiver apparatus, a configuration of one or more reference signals (RSs) from a transmitter apparatus, wherein the configuration indicates time and frequency information related to an irregular RS pattern of the one or more RSs;

receiving, by the processor, the one or more RSs based on the configuration from the transmitter apparatus; and

performing, by the processor, a sensing of a target object according to the one or more RSs.
The method of Claim 14, wherein the one or more RSs comprise a comb RS and a phase tracking reference signal (PTRS) -like RS.
The method of Claim 15, wherein the comb RS comprises at least one one of the following:

a demodulation reference signal (DMRS) ;

a channel state information-reference signal (CSI-RS) ;

a tracking reference signal (TRS) ; and

a positioning reference signal (PRS) .
The method of Claim 15, further comprising:

transmitting, by the processor, an indication that combining the comb RS and the PRTS for sensing is supported to the transmitter apparatus.
The method of Claim 14, wherein the irregular RS pattern is a generalized irregular RS pattern indicating that resource elements (REs) of the one or more RSs are not uniformly spaced either in each RS symbol or across RS symbols.
The method of Claim 18, further comprising:

transmitting, by the processor, an indication that the generalized irregular RS pattern for sensing is supported to the transmitter apparatus.
The method of Claim 14, wherein the sensing comprises at least one of a distance estimation and a velocity estimation of the target object.