US-20260128931-A1 - PULSE TRAIN TRANSMISSION METHOD AND COMMUNICATION APPARATUS

US20260128931A1US 20260128931 A1US20260128931 A1US 20260128931A1US-20260128931-A1

Abstract

A communication apparatus determines a first sequence group, where the first sequence group includes N sequences, where N is greater than 2 and is a power of 2, the N sequences include at least one Golay complementary sequence pair, each of the N sequences includes a plurality of symbols, and symbols in at least two sequences are arranged in opposite orders. The communication apparatus sends a pulse train, where the pulse train is obtained based on the first sequence group, and one pulse in the pulse train corresponds to one of the N sequences.

Inventors

Qi Feng
Fan Wang
Zhang Zhang
Dongdong Wei

Assignees

HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251222

Claims (20)

1 . A pulse train transmission method, comprising: determining a first sequence group, wherein the first sequence group comprises N sequences, wherein N is greater than 2 and is a power of 2, the N sequences comprise at least one Golay complementary sequence pair, each of the N sequences comprises a plurality of symbols, and symbols in at least two sequences are arranged in opposite orders; and sending a pulse train, wherein the pulse train is obtained based on the first sequence group, and one pulse in the pulse train corresponds to one of the N sequences.
2 . The method according to claim 1 , wherein lengths of the N sequences are equal.
3 . The method according to claim 1 , wherein the first sequence group comprises a first sequence and a second sequence, wherein the first sequence and the second sequence are Golay complementary sequences; and the first sequence group further comprises a third sequence and a fourth sequence, wherein a symbol arrangement order of the third sequence is opposite to that of the first sequence, and a symbol arrangement order of the fourth sequence is opposite to that of the second sequence.
4 . The method according to claim 3 , wherein a quantity of first sequences, a quantity of second sequences, a quantity of third sequences, and a quantity of fourth sequences that are comprised in the first sequence group are the same, wherein a first-order term of a phase in a Taylor expansion of an ambiguity function of the first sequence group at zero Doppler is set to zero.
5 . The method according to claim 3 , wherein if N=4, the first sequence, the second sequence, the fourth sequence, and the third sequence in the first sequence group are sequentially arranged; or if N>4, an arrangement order of first N/2 sequences in the first sequence group is the same as an arrangement order of sequences when the first sequence group comprises the N/2 sequences.
6 . The method according to claim 5 , wherein for N=4, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , ); or for N=8, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , , , , {right arrow over (x)}, {right arrow over (y)}); or for N=16, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , , , , {right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}, , , , , {right arrow over (y)}, {right arrow over (x)}), wherein {right arrow over (x)} represents the first sequence, {right arrow over (y)} represents the second sequence, represents the third sequence, and represents the fourth sequence.
7 . The method according to claim 5 , wherein if N≥16, an arrangement of the N sequences in the first sequence group satisfies the following rule: if sequence i in the first sequence group is the first sequence, sequence N/2+i is the second sequence; or if sequence i in the first sequence group is the second sequence, sequence N/2+i is the first sequence; or if sequence i in the first sequence group is the third sequence, sequence N/2+i is the fourth sequence; or if sequence i in the first sequence group is the fourth sequence, sequence N/2+i is the third sequence, wherein 0≤i<N/2, and i is an integer.
8 . The method according to claim 3 , wherein when N≥16, the quantity of first sequences, the quantity of second sequences, the quantity of third sequences, and the quantity of fourth sequences in the first sequence group are all N/4, and in the first sequence group, a sum of indexes of the N/4 first sequences in the first sequence group, a sum of indexes of the N/4 second sequences in the first sequence group, a sum of indexes of the N/4 third sequences in the first sequence group, and a sum of indexes of the N/4 fourth sequences in the first sequence group are the same.
9 . The method according to claim 3 , wherein the method further comprises: constructing, based on a PTM sequence, a second sequence group by using the first sequence and the second sequence, wherein the second sequence group comprises N/2 sequences; and constructing, based on the PTM sequence, a third sequence group by using the fourth sequence and the third sequence, wherein the third sequence group comprises N/2 sequences, wherein the first sequence group comprises the second sequence group and the third sequence group, wherein sequence i in the second sequence group is sequence 2i in the first sequence group, and sequence i in the third sequence group is a (2i+1) th sequence in the first sequence group, wherein 0≤i<N/2, and i is an integer.
10 . The method according to claim 9 , wherein for N=4, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}), the third sequence group is ( , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, ); or for N=8, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}), the third sequence group is ( , , , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (y)}, , {right arrow over (x)}, ); or for N=16, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}, {right arrow over (y)}, {right arrow over (x)}, {right arrow over (x)}, {right arrow over (y)}), the third sequence group is ( , , , , , , , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (y)}, , {right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (x)}, , {right arrow over (x)}, , {right arrow over (y)}, ), wherein {right arrow over (x)} represents the first sequence, {right arrow over (y)} represents the second sequence, represents the third sequence, and represents the fourth sequence.
11 . An apparatus, comprising: at least one processor; and a non-transitory computer-readable medium including computer-executable instructions that, when executed by the processor, cause the apparatus to carry out a method including: determining a first sequence group, wherein the first sequence group comprises N sequences, wherein N is greater than 2 and is a power of 2, the N sequences comprise at least one Golay complementary sequence pair, each of the N sequences comprises a plurality of symbols, and symbols in at least two sequences are arranged in opposite orders; and sending a pulse train, wherein the pulse train is obtained based on the first sequence group, and one pulse in the pulse train corresponds to one of the N sequences.
12 . The apparatus according to claim 11 , wherein lengths of the N sequences are equal.
13 . The apparatus according to claim 11 , wherein the first sequence group comprises a first sequence and a second sequence, wherein the first sequence and the second sequence are Golay complementary sequences; and the first sequence group further comprises a third sequence and a fourth sequence, wherein a symbol arrangement order of the third sequence is opposite to that of the first sequence, and a symbol arrangement order of the fourth sequence is opposite to that of the second sequence.
14 . The apparatus according to claim 13 , wherein a quantity of first sequences, a quantity of second sequences, a quantity of third sequences, and a quantity of fourth sequences that are comprised in the first sequence group are the same, wherein a first-order term of a phase in a Taylor expansion of an ambiguity function of the first sequence group at zero Doppler is set to zero.
15 . The apparatus according to claim 13 , wherein if N=4, the first sequence, the second sequence, the fourth sequence, and the third sequence in the first sequence group are sequentially arranged; or if N>4, an arrangement order of first N/2 sequences in the first sequence group is the same as an arrangement order of sequences when the first sequence group comprises the N/2 sequences.
16 . The apparatus according to claim 15 , wherein for N=4, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , ); or for N=8, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , , , , {right arrow over (x)}, {right arrow over (y)}); or for N=16, the first sequence group is ({right arrow over (x)}, {right arrow over (y)}, , , , , {right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}, , , , , {right arrow over (y)}, {right arrow over (x)}), wherein {right arrow over (x)} represents the first sequence, {right arrow over (y)} represents the second sequence, represents the third sequence, and represents the fourth sequence.
17 . The apparatus according to claim 15 , wherein if N≥16, an arrangement of the N sequences in the first sequence group satisfies the following rule: if sequence i in the first sequence group is the first sequence, sequence N/2+i is the second sequence; or if sequence i in the first sequence group is the second sequence, sequence N/2+i is the first sequence; or if sequence i in the first sequence group is the third sequence, sequence N/2+i is the fourth sequence; or if sequence i in the first sequence group is the fourth sequence, sequence N/2+i is the third sequence, wherein 0≤i<N/2, and i is an integer.
18 . The apparatus according to claim 13 , wherein when N≥16, the quantity of first sequences, the quantity of second sequences, the quantity of third sequences, and the quantity of fourth sequences in the first sequence group are all N/4, and in the first sequence group, a sum of indexes of the N/4 first sequences in the first sequence group, a sum of indexes of the N/4 second sequences in the first sequence group, a sum of indexes of the N/4 third sequences in the first sequence group, and a sum of indexes of the N/4 fourth sequences in the first sequence group are the same.
19 . The apparatus according to claim 13 , wherein the method further comprises: constructing, based on a PTM sequence, a second sequence group by using the first sequence and the second sequence, wherein the second sequence group comprises N/2 sequences; and constructing, based on the PTM sequence, a third sequence group by using the fourth sequence and the third sequence, wherein the third sequence group comprises N/2 sequences, wherein the first sequence group comprises the second sequence group and the third sequence group.
20 . The apparatus according to claim 19 , wherein for N=4, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}), the third sequence group is ( , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, ); or for N=8, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}), the third sequence group is ( , , , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (y)}, , {right arrow over (x)}, ); or for N=16, the second sequence group is ({right arrow over (x)}, {right arrow over (y)}, {right arrow over (y)}, {right arrow over (x)}, {right arrow over (y)}, {right arrow over (x)}, {right arrow over (x)}, {right arrow over (y)}), the third sequence group is ( , , , , , , , ), and the first sequence group is ({right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (y)}, , {right arrow over (x)}, , {right arrow over (y)}, , {right arrow over (x)}, , {right arrow over (x)}, , {right arrow over (y)}, ) wherein {right arrow over (x)} represents the first sequence, {right arrow over (y)} represents the second sequence, represents the third sequence, and represents the fourth sequence.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2023/102941, filed on Jun. 27, 2023, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the communication field, and more specifically, to a pulse train transmission method and a communication apparatus. BACKGROUND Sequences play a crucial role in a communication system. Mutual discovery, clock synchronization, ranging, speed measurement, and the like between communication devices may be implemented by using a sequence correlation, and pilot multiplexing may be implemented by using orthogonality of the sequences. Golay complementary sequence pairs are widely used in wireless fidelity (wireless fidelity, Wi-Fi) sensing systems, radar sensing systems, and the like due to ideal aperiodic autocorrelation properties of the Golay complementary sequence pairs and constant-modulus properties of binary sequences. An ambiguity function of Golay complementary sequences does not have a range sidelobe when a Doppler frequency shift is equal to zero, but exhibits large range sidelobes in other regions in which Doppler frequency shifts are not equal to zero. The Doppler frequency shift destroys ideal aperiodic autocorrelation properties of the Golay complementary sequence pair. To reduce range sidelobes, it is proposed that the Golay complementary sequence pair is extended by a Prouhet-Thue-Morse (Prouhet-Thue-Morse, PTM) sequence to obtain Doppler-resilient sequences, thereby achieving a low-ambiguity region around a main peak of the ambiguity function. A Golay complementary sequence group extended by the PTM sequence can be resilient to a Doppler frequency shift that exhibits stepwise phase variations over time. However, the phase variations caused by the Doppler frequency shift are usually continuous and linearly increase with time. Therefore, Golay complementary sequences extended by the PTM sequence cannot be resilient to a Doppler frequency shift with linear phase variations over time. SUMMARY Embodiments of this application provide a pulse train transmission method and a communication apparatus, which can be resilient to a Doppler frequency shift with linear phase variations, and can improve performance of target detection. According to a first aspect, a pulse train transmission method is provided. The method may be performed by a communication apparatus. The communication apparatus may be a communication device or a module (for example, a chip or a chip module) configured (or used) in a communication device. The method includes: The communication apparatus determines a first sequence group, where the first sequence group includes N sequences, where N is greater than 2 and is a power of 2, the N sequences include at least one Golay complementary sequence pair, each of the N sequences includes a plurality of symbols, and symbols in at least two sequences are arranged in opposite orders. The communication apparatus sends a pulse train, where the pulse train is obtained based on the first sequence group, and one pulse in the pulse train corresponds to one of the N sequences. According to the foregoing solution, by using a property that a Golay complementary sequence pair remains a Golay complementary sequence pair after symbols in one sequence or both sequences are arranged in a reverse order, it is proposed that a pulse train resilient to a Doppler frequency shift with linear phase variations should be obtained through extension based on the Golay complementary sequence pair and symbol reversal, thereby improving performance of target detection. With reference to the first aspect, in some implementations of the first aspect, the method further includes: The communication apparatus receives an echo signal of the pulse train. The communication apparatus determines a range and/or a speed based on the echo signal. According to the foregoing solution, the communication apparatus may obtain a speed and/or a range of a target by receiving the echo signal of the pulse train. Because the pulse train can be resilient to a Doppler frequency shift with linear variations, high measurement accuracy can be obtained based on the pulse train. With reference to the first aspect, in some implementations of the first aspect, lengths of the N sequences are equal. With reference to the first aspect, in some implementations of the first aspect, the first sequence group includes a first sequence and a second sequence, where the first sequence and the second sequence are Golay complementary sequences. The first sequence group further includes a third sequence and a fourth sequence, where a symbol arrangement order of the third sequence is opposite to that of the first sequence, and a symbol arrangement order of the fourth sequence is opposite to that of the second sequence. With reference to the first aspect, in some implementations of the first aspect, a quant