Generate a sequence for reference signal

Abstract

Methods, systems and apparatus for generating sequence pairs for reference signals in mobile communication technologies are described. An exemplary wireless communication method includes: transmitting reference signals with wireless nodes on multiple subcarriers using digital modulation technology, wherein the reference signals include M (M≥2) sequences, and the M sequences are selected based on searching a sequence set in a manner such that the M sequences satisfy at least one search termination condition.

Description

Technical Field

[0001] This document generally relates to wireless communications. Background Art

[0002] Wireless communication technologies are driving the world towards an increasingly connected and networked society. The rapid growth of wireless communications and technological advances have led to greater demands for capacity and connectivity. Other aspects such as energy consumption, device cost, spectrum efficiency, and latency are also important to meet the needs of various communication scenarios. Compared to existing wireless networks, next-generation systems and wireless communication technologies need to provide support for an increased number of users and devices, as well as support for higher data rates, requiring user equipment to implement energy-saving techniques. Summary of the invention

[0003] The present invention relates to methods, systems and apparatus for generating sequences for reference signals in mobile communication technologies, including 5th generation (5G) communication systems and new radio (NR) communication systems. In one exemplary aspect, a wireless communication method is disclosed. The method includes: transmitting a reference signal with a wireless node on multiple subcarriers using a digital modulation technique, wherein the reference signal includes M (M≥2) sequences, and the M sequences are selected based on searching a sequence set in a manner such that the M sequences satisfy at least one search termination condition.

[0004] In another exemplary aspect, a wireless communication method may include: receiving data and a reference signal using multiple subcarriers at a wireless node, wherein the reference signal includes M sequences on M (M≥2) symbols and is used to demodulate the data; and detecting the reference signal based at least in part on searching a set of sequences in a manner such that the M sequences satisfy at least one condition.

[0005] In yet another exemplary aspect, the M sequences include at least one pair of sequences A, B arranged in a hopping A, B, A, B, A, B, . . . repeating pattern.

[0006] In another exemplary aspect, the above method is embodied in the form of processor executable code and stored in a computer readable program medium.

[0007] In yet another exemplary aspect, a device configured or operable to perform the above method is disclosed.

[0008] The above and other aspects and embodiments thereof are described in more detail in the drawings, the following description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Examples of a base station (BS) and a user equipment (UE) in wireless communications according to some embodiments of the disclosed technology are shown.

[0010] Figure 2 is a block diagram of an example implementation of a wireless communication device.

[0011] Figure 3A and Figure 3B is a block diagram representation of a portion of a device according to some embodiments of the disclosed technology.

[0012] Figure 4 An example of a wireless communication method according to some embodiments of the disclosed technology is shown. DETAILED DESCRIPTION

[0013] The demand for the 4th Generation mobile communication technology (4G), Long-Term Evolution (LTE), Long-Term Evolution Advanced (LTE-Advanced / LTE-A) and the 5th Generation mobile communication technology (5G) is increasing. From the current development trend, 4G and 5G systems are studying features that support enhanced mobile broadband, ultra-high reliability, ultra-low latency transmission and massive connections.

[0014] In the new generation of NR (New Radio) technology, the physical uplink control channel (PUCCH) and the physical uplink shared channel (PUSCH) support π / 2-BPSK modulation to further reduce the peak-to-average power ratio (PAPR) of the signal. π / 2-BPSK is generated from the standard BPSK signal by multiplying the symbol sequence with a rotating phasor with a phase increment of π / 2 per symbol period. π / 2-BPSK has the same bit error rate performance as BPSK on a linear channel, however, it exhibits less envelope variation (ie, PAPR), making it more suitable for transmission with nonlinear channels. This improves the power amplifier efficiency cost in mobile terminals at lower data rates.

[0015] π / 2-BPSK modulation is used to modulate the data portion of the signal, while the reference signal (or referred to herein as a DMRS (demodulation reference signal) signal) still uses a Zadoff-Chu (ZC) sequence or a QPSK-based computer-generated sequence (referred to as a CGS sequence). The current implementation has shown that if the data portion uses π / 2-BPSK modulation and the reference signal uses a ZC sequence or a CGS sequence, the PAPR between the data portion and the reference signal is different, wherein the PAPR of the data portion is lower than the PAPR of the reference signal. In the current implementation, when a user sends a PUSCH or a PUCCH, the power can only be adjusted for the entire PUSCH or PUCCH; that is, the transmission power of a specific symbol cannot be adjusted separately. Therefore, the PAPR of the data portion is not equal to the PAPR of the reference signal portion, resulting in that the low PAPR performance of the π / 2-BPSK modulation is not fully utilized, because the power adjustment is based on the higher PAPR of the reference signal. Therefore, higher requirements are placed on the design of the reference signal. As a result, the design of a sequence with a low peak-to-average ratio becomes a problem to be solved. In addition, when the reference signal includes at least two sequences (for example, in two symbols), it is another problem to be solved to identify and / or combine the two sequences for better performance. This patent document particularly solves this demand. This article is directed to selecting a sequence pair from a set of sequences so that at least one search termination condition is achieved or satisfied, thereby producing better system performance. In some embodiments, the search termination condition may be related to a joint autocorrelation condition associated with the sequence pair. In some embodiments, the search termination condition may be related to the length of the sequence in the sequence pair. It should be understood that although the discussion herein is based on sequence pairs, such discussion is for illustrative purposes only. In some embodiments, for example, the sequence pair may be included in the reference signal as M sequences, which are arranged in a repetitive hopping pattern represented as A, B, A, B, ...

[0016] Embodiments of the disclosed technology

[0017] Figure 1 An example of a wireless communication system (e.g., LTE, 5G, or New Radio (NR) cellular network) including a base station (BS) 120 and one or more user equipments (UEs) 111, 112, and 113 is shown. In some embodiments, uplink transmissions (131, 132, 133) include a data portion modulated by π / 2 BPSK and a reference signal including a sequence described by the disclosed technology. The UE may be, for example, a smart phone, a tablet, a mobile computer, a machine-to-machine (M2M) device, a terminal, a mobile device, an Internet of Things (IoT) device, etc.

[0018] This document uses section headings and subheadings for ease of understanding, rather than limiting the scope of the disclosed techniques and embodiments to certain sections. Therefore, the embodiments disclosed in different sections can be used together. In addition, examples from the 3GPP New Air (NR) network architecture and 5G protocols are used herein only to aid understanding, and the disclosed techniques and embodiments can be practiced in other wireless systems that use communication protocols different from the 3GPP protocols.

[0019] Figure 2 A block diagram representing the architecture of a communication device such as a user equipment (UE) terminal or a wireless communication device 200 is described. The terminal 200 may include one or more processor electronics 210, such as a microprocessor that implements one or more of the wireless technologies presented herein. The terminal 200 may include a transmitter electronics 215 and a receiver electronics 220 to send and / or receive wireless signals through one or more communication interfaces such as an antenna 220. In some embodiments, the transmitter electronics 215 and the receiver electronics 220 may be integrated into a single electronic transceiver unit or module. The terminal 200 may include other communication interfaces for sending and receiving data. The terminal 200 may include one or more memories 205, which are configured to store information such as data and / or instructions related to the methods disclosed herein. In some embodiments, the processor electronics 210 may include at least a portion of the transceiver electronics. In some embodiments, a sequence generation module 225 is used to implement at least some of the disclosed techniques, modules, or functions.

[0020] Implementation of generating reference signal

[0021] Figure 3A and 3B is a block diagram representation of a portion of a device according to some embodiments of the disclosed technology. For example, Figure 3A Schematic diagram of generating a reference signal based on π / 2-BPSK. The binary sequence b(n) is modulated by the π / 2-BPSK modulation module 302, and an output sequence d(n) is generated. Then, d(n) is precoded by a DFT operation in a DFT (Discrete Fourier Transform) module 304, and then mapped to REs for transmission in the frequency domain by a resource element (RE) mapping module 306. The RE mapping module 306 is connected to an IFFT (Inverse Fast Fourier Transform) module 308 for IFFT operation. The output of the IFFT module 308 corresponds to a time domain sequence. RE mapping and IFFT in the frequency domain are similar to the generation of OFDM (Orthogonal Frequency Division Multiplexing) signals.

[0022] The relationship between d(n) and b(n) for π / 2-BPSK is given by:

[0023]

[0024] Where exp() is the exponential function and mod is the modular operation.

[0025] When the length of the reference signal is relatively short, for example, shorter than 30, a computer generated sequence (CGS) can be used as the symbol of the reference signal. In order to obtain the desired / target sequence, various sequence selection criteria can be used during the search process, such as low PAPR, low autocorrelation, and low cross-correlation between two sequences. In order to generate the sequence, the bit stream b listed in Table 1, Table 2 and Table 3 u (n) can be used with π / 2-BPSK modulation techniques with lengths of 12, 18, and 24 respectively.

[0026] Table 1: CGS for π / 2-BPSK with N=12

[0027]

[0028]

[0029] Table 2: CGS for π / 2-BPSK with N=18

[0030]

[0031] Table 3: CGS for π / 2-BPSK with N=24

[0032]

[0033] Figure 3B An example of reference signal generation based on 8-PSK modulation technique is shown. The reference signal generated using 8-PSK is similar to π / 2-BPSK, for example, π / 2-BPSK modulation module 302 is replaced by 8-PSK modulation module 301. Various sequence selection criteria can be used during the search process, such as low PAPR, low autocorrelation, and low cross-correlation between two sequences.

[0034] The relationship between d(n) and b(n) of 8-PSK can be expressed by equation (2). To generate the sequence, the bit stream b listed in Table 4 is u (n) can be used with 8-PSK modulation technique with length N=6.

[0035]

[0036] Table 4: CGS for 8-PSK with N=6

[0037]

[0038] Embodiments for selecting at least one pair of sequences

[0039] In the current NR specification, one-symbol DMRS (e.g., when the reference signal includes a single sequence) and two-symbol DMRS (e.g., when the reference signal includes two sequences) are supported for PUSCH. In the case of two-symbol DMRS, two options are disclosed in this patent document:

[0040] • Option 1: Design a new sequence for two DMRS symbols that satisfies a predefined condition for joint autocorrelation. In some embodiments, the sequence set used in designing a two-symbol DMRS is different from the sequence set used in designing a one-symbol DMRS.

[0041] • Option 2: Design a deterministic sequence pair for two DMRS symbols that satisfies a predefined condition for joint autocorrelation. In some embodiments, the sequence set used in designing a two-symbol DMRS may be the same sequence set as the sequence set used in designing a one-symbol DMRS.

[0042] One advantage of Option 2 over Option 1 is that a single sequence set can be used for both one-symbol DMRS and two-symbol DMRS, which saves memory (e.g., storage requirements) at the UE and / or base station (gNB). Therefore, this document discloses how to design / select a two-symbol DMRS. For example, this document discusses how to select a sequence pair from a sequence set so that the sequence pair can satisfy one or more search termination conditions. It should be understood that although the discussion herein is based on sequence pairs, such discussion is for illustrative purposes only. In some embodiments, for example, the sequence pairs may be included in a reference signal as M sequences arranged in a repeating hopping pattern represented as A, B, A, B, ... In some embodiments, the M sequences may be based at least in part on an identification of at least a cell, a user, or a communication channel.

[0043] The autocorrelation of the series can be expressed as:

[0044]

[0045] Among them, d(.) represents the sequence, d(.)* represents the conjugate of d(.), N represents the length of the sequence, and j is the cyclic shift.

[0046] If the series has perfect autocorrelation, then In practice, it may be extremely difficult to generate a sequence with zero autocorrelation. For example, the sequences based on π / 2-BPSK (listed in Tables 1 to 3) and the sequences based on 8-PSK (listed in Table 4) do not have perfect autocorrelation. Therefore, in some embodiments using two DMRS symbols, a joint or combined autocorrelation may be used as a criterion for determining the sequence pair to be used in the two DMRS symbols. Therefore, a perfect (equal to zero) or nearly perfect (close to zero) joint autocorrelation is desired.

[0047] The joint autocorrelation of a pair of sequences can be defined as:

[0048]

[0049] where d a (.) and d b (.) are two sequences used in two DMRS symbols.

[0050] This article is directed to selecting (or searching for) a sequence pair (referred to herein as a winning pair) in a set of computer-generated sequences so as to achieve a desired search termination condition. For example, the search termination condition can be based on a joint autocorrelation condition. For example, if the sequence set is represented as S1, S2, S3, the joint autocorrelation of (S1, S2), (S1, S3) and (S2, S3) is calculated. These calculations are repeated on one or more cyclic shifts of S1, S2, S3. In this article, several embodiments for selecting a winning sequence pair are discussed. They are described as follows.

[0051] Embodiment 1: Calculate the joint autocorrelation of each sequence pair in the sequence set. Then, based on the joint autocorrelation value, select the sequence pair with the maximum number of zero (or near zero) joint autocorrelation values ​​on one or more cyclic shifts as the winning pair. The near zero condition can be achieved by checking that the joint autocorrelation value does not exceed 0.00001. In this embodiment, the search termination condition is based on the maximum number of zero (or near zero) joint autocorrelation values.

[0052] Embodiment 2: Calculate the joint autocorrelation of each sequence pair in the sequence set. Then, based on the joint autocorrelation value, select the sequence pair with the smallest maximum joint autocorrelation (e.g., below a threshold) on one or more cyclic shifts as the winning pair. In this embodiment, the search termination condition is based on the minimum value of the maximum joint autocorrelation values.

[0053] Embodiment 3: Calculate the joint variance of each sequence pair in the sequence set. Then, based on the joint variance value, select the sequence pair with the smallest maximum joint variance (e.g., below a threshold) on one or more cyclic shifts as the winning pair. In this embodiment, the search termination condition is based on the minimum value of the maximum joint variance values.

[0054] Embodiments 1 to 3 may be implemented individually or in combination. An example of a combined embodiment is discussed next.

[0055] Embodiment 4: A first combination of Embodiment 1 and Embodiment 2.

[0056] Step 1: Calculate the joint autocorrelation of each sequence pair in the sequence set based on equation (4) in all cyclic shifts or specific cyclic shifts. Record the maximum joint autocorrelation value of the pair in a first table (e.g., Table 5A) in all cyclic shifts or specific cyclic shifts. Record the number of pairs of zero (or near-zero) joint autocorrelation values ​​in a second table (e.g., Table 5B) in all cyclic shifts or specific cyclic shifts.

[0057] ·Step 2: Exclude from the first table those sequence pairs with high joint autocorrelation, e.g., sequences with joint autocorrelation above a threshold. The threshold may be at least partially related to the length of the sequences in the sequence set (denoted as N). For example, when N=12 and a π / 2-binary phase shift keying (BPSK) modulation technique is used, the threshold may be 0.3333. When N=18 and a π / 2-binary phase shift keying (BPSK) modulation technique is used, the threshold may be 0.2222. When N=24 and a π / 2-binary phase shift keying (BPSK) modulation technique is used, the threshold may be 0.25. When N=6 and an 8-PSK modulation technique is used, the threshold may be 0.4714. The remaining sequence pairs are marked as a candidate set of sequence pairs for subsequent selection.

[0058] Step 3: Perform sequence pairing across a set of sequences until a sequence pair with the smallest maximum joint autocorrelation can be selected from the first table. If a sequence (e.g., Sx) has been selected to be paired with another sequence (e.g., Sy), all sequence pairs with sequence Sx can be excluded from the candidate set. The candidate set of sequence pairs is updated, and step 3 is repeated until all sequences in the set have been paired. In some scenarios, multiple sequences may have the same maximum joint autocorrelation value for a given pair. Therefore, in order to break ties, a sequence pair with the largest number of zero (or near-zero) joint autocorrelation values ​​is selected, as indicated in the second table. However, if there is another tie in which even the number of zero (or near-zero) joint autocorrelations is the same between multiple sequences, one of the multiple sequences is randomly selected for pairing with the given sequence. For example, given sequence S1, if the sequence pairs (S1, S2), (S1, S3), (S1, S4) have the same maximum joint autocorrelation, the second table is used to determine the number of zero (or near zero) joint autocorrelation values ​​of the sequence pairs (S1, S2), (S1, S3), (S1, S4). If the number of zero (or near zero) joint autocorrelation values ​​of (S1, S2), (S1, S3), (S1, S4) is assumed to be 10, 12, 11, respectively, then sequence S3 is selected to pair with S1.

[0059] Embodiment 5: A second combination of Embodiment 1 and Embodiment 2.

[0060] Step 1: Calculate the joint autocorrelation of each sequence pair in the sequence set based on equation (4) in all cyclic shifts or specific cyclic shifts. Record the maximum joint autocorrelation value of the pair in a first table (e.g., Table 5A) in all cyclic shifts or specific cyclic shifts. Record the number of pairs of zero (or near-zero) joint autocorrelation values ​​in a second table (e.g., Table 5B) in all cyclic shifts or specific cyclic shifts.

[0061] Step 2: exclude from the second table those sequence pairs that have a small number of zero (or near zero) joint autocorrelation values ​​(e.g., the number of zero (or near zero) joint autocorrelation values ​​does not exceed a threshold). The threshold may be at least partially related to the length of the sequences in the sequence set (denoted as N). The remaining sequence pairs are marked as a candidate sequence pair set for further down selection.

[0062] Step 3: Perform sequence pairing across the sequence set until a sequence pair with the maximum number of zero (or near-zero) joint autocorrelation values ​​can be selected from the second table. If a sequence (e.g., Sx) paired with another sequence (e.g., Sy) has been selected, all sequence pairs with sequence Sx can be excluded from the candidate set. The sequence pair candidate set is updated, and step 3 is repeated until all sequences in the set have been paired. In some scenarios, given the sequences in a pair, multiple sequences may have the same maximum number of zero (or near-zero) joint autocorrelation values. Therefore, in order to break the tie, the sequence pair with the smallest maximum joint autocorrelation is selected, as indicated in the first table. However, if there is another tie in which even the maximum joint autocorrelation is the same between multiple sequences, one of the multiple sequences is randomly selected for pairing with the given sequence.

[0063] Table 5A: First table in Embodiment 1, where N=12

[0064]

[0065] Table 5B: Second table in Embodiment 1, where N=12

[0066]

[0067] Tables 5A and 5B correspond to the first and second tables in Embodiments 4 and 5, each of which has 30 rows and 30 columns corresponding to a sequence set of 30 sequences. As an example for discussion, if sequence 0 (i.e., the first column) is considered for the first symbol, Table 5B indicates that the maximum number of zero joint autocorrelation values ​​is 10. In other words, for the sequence pairs (0, 0), (0, 2), (0, 4), (0, 15), (0, 16), and (0, 18), there are 10 cyclic shifts with zero joint autocorrelation values, implying that the second symbol can be selected from sequences 0, 2, 4, 15, 16, and 18. When performing a search, 30 sequences are collectively considered for the search termination to be reached.

[0068] Because the joint variance of each sequence pair can be calculated based on the joint autocorrelation, the details of the process of embodiment 3 can be inferred from the process of embodiment 2. In this article, embodiment 4 or 5 is used as an example of selecting a winning sequence pair to be included in a DMRS symbol (for example, as shown in Tables 6A, 7A, 8A, and 9A). The first sequence is used in the first DMRS symbol, and the second sequence is used in the second DMRS symbol. The CGS index of the winning sequence pair is listed in Tables 6A, 7A, 8A, and 9A. Specifically, Tables 6A, 7A, and 8A respectively show the winning sequence pairs for sequence lengths of 12, 18, and 24 when the digital modulation technique is π / 2-binary phase shift keying (BPSK) and the size of the sequence set is 30. Table 9A shows the winning sequence pair for a sequence length of 6 when the digital modulation technique is 8-PSK and the size of the sequence set is 30.

[0069] Tables 6B, 7B, 8B, 9B show the average (i.e., mean) and maximum joint autocorrelation values ​​for the winning pairs listed in Tables 6A, 7A, 8A, 9A, respectively. For comparison purposes, the autocorrelation of a single symbol DMRS is also listed. Tables 6B, 7B, 8B, 9B indicate that the mean and maximum values ​​of the joint autocorrelation of the two-symbol DMRS are reduced compared to the single-symbol DMRS. A lower joint autocorrelation means a flatter frequency response, which results in better channel estimation performance. Therefore, the design / selection of the winning pairs as disclosed herein provides at least one patentable benefit.

[0070] Table 6A: CGS pairing table showing indices of winning sequence pairs for N=12

[0071]

[0072]

[0073] Table 6B: Autocorrelation values ​​for winning pairs in Table 5A

[0074]

[0075] Table 7A: CGS pairing table showing indices of winning sequence pairs for N=18

[0076]

[0077]

[0078] Table 7B: Joint autocorrelation values ​​for winning pairs in Table 6A

[0079]

[0080] Table 8A: CGS pairing table showing indices of winning sequence pairs for N=24

[0081]

[0082]

[0083]

[0084] Table 8B: Autocorrelation values ​​for winning pairs in Table 7A

[0085]

[0086]

[0087] Table 9A: CGS pairing table showing indices of winning sequence pairs for N=6

[0088]

[0089]

[0090] Table 9B: Joint autocorrelation values ​​for winning pairs in Table 8A

[0091]

[0092] In some embodiments, two DMRS symbols may be adjacent or non-adjacent to each other in the time domain. In some embodiments, the maximum joint autocorrelation value is associated with a cyclic shift varying from 1 to (N-1). In some embodiments, the maximum joint autocorrelation value is associated with a predetermined cyclic shift based at least in part on N, for example, the predetermined cyclic shift may be: when N is 6, j=1, when N is 12, j=2 or 3, when N is 18, j=4 or 5, when N is 24, j=5 or 6.

[0093] Exemplary Methods of the Disclosed Technology

[0094] Figure 4 An example of a wireless communication method 400 for generating a winning sequence pair for use in a reference signal in a mobile communication technology is shown. The method 400 includes: at step 410, a reference signal is sent from a wireless node using a digital modulation technique, wherein the reference signal includes M sequences (M≥2) based on searching a sequence set in a manner such that the M sequences satisfy at least one condition.

[0095] In some embodiments, a method may be implemented at a receiving wireless node. The method may include: receiving data and a reference signal using multiple subcarriers, wherein the reference signal includes M sequences (M≥2) on M symbols and is used to demodulate the data; and detecting the reference signal based at least in part on searching a set of sequences in a manner such that the M sequences satisfy at least one condition.

[0096] In some embodiments, data and reference signals are transmitted on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH). In other embodiments, the data includes uplink traffic data and uplink control information. In other embodiments, the reference signal is used to demodulate the data. In one aspect, the sequences described and constructed by embodiments of the disclosed technology advantageously achieve improved demodulation performance due to their PAPR and autocorrelation characteristics.

[0097] Instructions and Appendix Figure 1 The examples should be considered as merely exemplary, where exemplary means examples and does not imply ideal or preferred embodiments unless otherwise specified. As used herein, the use of "or" is intended to include "and / or" unless the context clearly dictates otherwise.

[0098] Some embodiments described herein are described in the general context of methods or processes, which in one embodiment can be implemented by a computer program product contained in a computer-readable medium, which includes computer-executable instructions, such as program code, executed by a computer in a networked environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. In general, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer or processor executable instructions, related data structures, and program modules represent examples of program codes for performing the steps of the methods disclosed herein. A specific sequence of such executable instructions or related data structures represents an example of corresponding actions for implementing the functions described in these steps or processes.

[0099] Some disclosed embodiments can be implemented as devices or modules using hardware circuits, software or a combination thereof. For example, a hardware circuit implementation may include discrete analog and / or digital components, for example, integrated as a part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some embodiments may additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionality of the present application. Similarly, various components or subcomponents within each module may be implemented in software, hardware or firmware. The connection between the modules and / or the components within the modules may be provided using any of the connection methods and media known in the art, including but not limited to communication using appropriate protocols through the Internet, wired or wireless networks.

[0100] Although many details are included herein, these details should not be interpreted as limitations on the scope of the claimed invention or the scope that may be claimed, but should be interpreted as descriptions of features peculiar to a particular embodiment. Certain features described herein in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations, and even initially claimed as such, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may be for a variation of a sub-combination or a sub-combination. Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a continuous order, or requiring all operations shown to be performed to achieve desired results.

[0101] Only a few implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this disclosure.

Claims

1. A wireless communication method, comprising: A reference signal is sent from a wireless node using a digital modulation technique, wherein the reference signal includes M sequences, M is greater than or equal to 2, and the M sequences are acquired based on searching a sequence set in a manner such that the M sequences satisfy at least one condition. The at least one condition associated with the M sequences is: a joint autocorrelation value, which is calculated as: Among them, d a (.) and d b (.) represents a sequence pair in the M sequences, j is the cyclic shift of the two sequences, N is the length of the sequence in the sequence pair, Wherein, when calculating the entire sequence set, for each cyclic shift of the sequence pair, The at least one condition is satisfied if the sequence pair has the largest number of zero joint autocorrelation values, or, The at least one condition is satisfied if the sequence pair has the minimum value of the maximum joint autocorrelation value, or, The at least one condition includes a first condition and a second condition, the first condition being satisfied if the sequence pair has a maximum number of zero joint autocorrelation values, and the second condition being satisfied if the sequence pair has a minimum value of a maximum joint autocorrelation value.

2. The method according to claim 1, wherein: The maximum joint autocorrelation value is associated with each of the cyclic shifts varying from 1 to (N-1).

3. The method according to claim 1, wherein: The maximum joint autocorrelation value is associated with a predetermined cyclic shift based at least in part on N.

4. The method according to claim 3, wherein: The predetermined cyclic shift includes: when N is 6, j=1, when N is 12, j=2 or 3, when N is 18, j=4 or 5, and when N is 24, j=5 or 6.

5. The method according to claim 1, wherein: The M sequences are obtained based at least in part on an identification of at least a cell, a user, or a communication channel.

6. The method according to claim 1, wherein: The wireless node is a user equipment (UE) or a base station.

7. The method according to claim 1, wherein: The digital modulation technique is π / 2-binary phase shift keying (BPSK), and the size of the sequence set is 30, and N is equal to 12, 18, or 24.

8. The method according to claim 1, wherein: The digital modulation technique is octal phase shift keying (8-PSK), and the size of the sequence set is 30, and N is equal to 6.

9. The method according to claim 7, wherein: Each sequence in the sequence set corresponds to the following mathematical form: Among them, exp() is the exponential function, mod is the modular operation, j is the imaginary unit, b u (n) is the u-th sequence in the sequence set, where u is an integer indexing each sequence in the sequence set, and u=0, 1, ..., 29, and where n varies from 0 to N-1.

10. The method according to claim 8, wherein: in, Each sequence in the sequence set corresponds to the following mathematical form: Among them, exp() is the exponential function, mod is the modulus operation, b u (n) is the u-th sequence in the sequence set, where u is an integer indexing each sequence in the sequence set, and u=0, 1, ..., 29, and where n varies from 0 to N-1.

11. The method according to claim 7, wherein: N=12, and wherein, when M=2, the reference signal is a demodulation reference signal (DMRS), which includes a first DMRS symbol and a second DMRS symbol identifiable by a computer generated sequence (CGS) index, the CGS index including at least one of the following CGS indexes:

12. The method according to claim 7, wherein: N=18, and wherein, when M=2, the reference signal is a demodulation reference signal (DMRS), which includes a first DMRS symbol and a second DMRS symbol identifiable by a computer generated sequence (CGS) index, the CGS index including at least one of the following CGS indexes:

13. The method according to claim 7, wherein: N=24, and wherein, when M=2, the reference signal is a demodulation reference signal (DMRS), which includes a first DMRS symbol and a second DMRS symbol identifiable by a computer generated sequence (CGS) index, the CGS index including at least one of the following CGS indexes:

14. The method according to claim 8, wherein: When M=2, the reference signal is a demodulation reference signal (DMRS), which includes a first DMRS symbol and a second DMRS symbol identifiable by a computer generated sequence (CGS) index, and the CGS index includes at least one of the following CGS indexes:

15. The method according to claim 1, wherein: The zero joint autocorrelation value includes a joint autocorrelation value that is zero or close to zero.

16. The method according to claim 1, wherein: The maximum joint autocorrelation values ​​include joint autocorrelation values ​​below a specified threshold.

17. The method according to claim 16, wherein: When N=2, the specified threshold is 0.3333; when N=18, the specified threshold is 0.2222; when N=24, the specified threshold is 0.25; and, when N=6, the specified threshold is 0.4714.

18. A wireless communication method, comprising: Receiving data and a reference signal at a wireless node using a plurality of subcarriers, wherein the reference signal comprises M sequences over M symbols and is used to demodulate the data, M being greater than or equal to 2; and detecting the reference signal based at least in part on searching a set of sequences in a manner such that the M sequences satisfy at least one condition, The at least one condition associated with the M sequences is: a joint autocorrelation value, which is calculated as: Among them, d a (.) and d b (.) represents a sequence pair in the M sequences, j is the cyclic shift of the two sequences, N is the length of the sequence in the sequence pair, Wherein, when calculating the entire sequence set, for each cyclic shift of the sequence pair, The at least one condition is satisfied if the sequence pair has the largest number of zero joint autocorrelation values, or, The at least one condition is satisfied if the sequence pair has the minimum value of the maximum joint autocorrelation value, or, The at least one condition includes a first condition and a second condition, the first condition being satisfied if the sequence pair has a maximum number of zero joint autocorrelation values, and the second condition being satisfied if the sequence pair has a minimum value of a maximum joint autocorrelation value.

19. The method according to any one of claims 1 to 18, wherein: The M sequences are adjacent to each other or not adjacent to each other in time domain representation.

20. The method according to claim 1, wherein: The M sequences include at least one pair of sequences A and B, and the at least one pair of sequences A and B are arranged in a jumping and repeating pattern of A, B, A, B, A, B, . . .

21. The method according to any one of claims 1 to 18 and 20, wherein The reference signal is sent on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

22. The method according to claim 7 or 11, wherein: The sequence set corresponds to:

23. The method according to claim 7 or 12, wherein: The sequence set corresponds to:

24. The method according to claim 7 or 13, wherein: The sequence set corresponds to:

25. The method according to claim 8 or 14, wherein: The sequence set corresponds to:

26. A wireless communication device comprising a memory and a processor, wherein the processor reads a code from the memory and implements the method according to any one of claims 1 to 25.

27. A computer-readable program storage medium having codes stored thereon, wherein when the codes are executed by a processor, the processor is caused to implement the method according to any one of claims 1 to 25.

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