# US 10,312,990 B2 · Signal sending or receiving method and device

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- Number: US 10,312,990 B2
- Document ID: US10312990B2
- Status: Granted
- Kind: B2
- Application number: 15/909,732
- Filed: 2018-03-01
- Published: 2018-07-05
- Granted: 2019-06-04
- Earliest claimed: 2015-09-02
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Bingyu Qu; Jianqin Liu; Kunpeng Liu; Yongxing Zhou
- Web page: https://patentgrep.com/patent/US10312990B2

## CPC

- H04B 7/12: Frequency diversity
- H04B 7/0684: {using different training sequences per antenna}
- H04B 7/26: at least one of which is mobile
- H04L 27/2614: {Peak power aspects}
- H04L 27/2621: {Reduction thereof using phase offsets between subcarriers}
- H04L 27/3411: {reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set}
- H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 27/2636: {with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]}
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A signal sending method includes: mapping, by a sending device, a first sequence onto M even-numbered subcarriers in 2M subcarriers, and mapping a second sequence onto M odd-numbered subcarriers in the 2M subcarriers, where the first sequence is one of a third sequence and a fourth sequence, the second sequence is the other of the third sequence and the fourth sequence, the 2M subcarriers are subcarriers on a same time domain symbol, and for elements of a second time domain sequence corresponding to the fourth sequence and a first time domain sequence corresponding to the third sequence at a same moment, when a complex factor is taken out, one of the first time domain sequence and the second time domain sequence is an in-phase component, and the other is a quadrature component; and transforming sequences mapped onto the 2M subcarriers to a time domain to generate transmit signals, and then sending the transmit signals.

## Claims

### Claim 1

A signal sending method, comprising:
mapping, by a sending device, a first sequence onto M even-numbered subcarriers in 2M subcarriers, and mapping a second sequence onto M odd-numbered subcarriers in the 2M subcarriers, wherein the first sequence is one of a third sequence and a fourth sequence, the second sequence is the other of the third sequence and the fourth sequence, the 2M subcarriers are subcarriers on a same time domain symbol, the fourth sequence is a sequence carrying M first information elements, and for elements of a second time domain sequence corresponding to the fourth sequence and a first time domain sequence corresponding to the third sequence at a same moment, when a complex factor is taken out, one of the first time domain sequence and the second time domain sequence is an in-phase component, and the other is a quadrature component;
transforming, by the sending device, sequences mapped onto the 2M subcarriers to a time domain to generate transmit signals; and
sending, by the sending device, the transmit signals.

### Claim 2 (depends on 1)

The method according to claim 1, wherein:
the first sequence is the third sequence, and the second sequence is the fourth sequence; and
before mapping the second sequence onto M odd-numbered subcarriers in the 2M subcarriers, the method further comprises:
performing, by the sending device, a first joint transform on the second time domain sequence to obtain the second sequence, wherein the first joint transform is a joint transform of a first phase rotation and an M×M discrete Fourier transform (DFT).

### Claim 3 (depends on 2)

The method according to claim 2, wherein:
the first time domain sequence is a sequence obtained by performing an inverse discrete Fourier transform (IDFT) on the first sequence; and
first phase rotations corresponding to M elements of the first time domain sequence are respectively e−j×2tπ/2M, wherein t=0, 1, . . . , M−1.

### Claim 4 (depends on 1)

The method according to claim 1, wherein:
a length of the second time domain sequence is M, the fourth sequence is M odd-numbered elements of a sequence obtained by performing a 2M×2M DFT on an extended sequence of the second time domain sequence, a length of the extended sequence of the second time domain sequence is 2M, and the last M elements of the extended sequence of the second time domain sequence are respectively opposite numbers of M elements of the second time domain sequence; and
a length of the first time domain sequence is M, the third sequence is M even-numbered elements of a sequence obtained by performing a 2M×2M DFT on an extended sequence of the first time domain sequence, a length of the extended sequence of the first time domain sequence is 2M, and the last M elements of the extended sequence of the first time domain sequence are respectively the same as M elements of the second time domain sequence.

### Claim 5 (depends on 4)

The method according to claim 4, wherein
before mapping, by the sending device, the first sequence onto M even-numbered subcarriers in 2M subcarriers and mapping the second sequence onto M odd-numbered subcarriers in the 2M subcarriers, the method further comprises:
obtaining, by the sending device, the first time domain sequence x(k) and the second time domain sequence y(k), and
extending, by the sending device, both the first time domain sequence x(k) and the second time domain sequence y(k) into sequences with lengths of 2M, wherein an extension manner of the first time domain sequence is x(k+M)=x(k), wherein k=0, 1, . . . , M−1, and an extension manner of the second time domain sequence is y(k+M)=−y(k), wherein k=0, 1, . . . , M−1; and
mapping, by the sending device, the first sequence onto M even-numbered subcarriers in 2M subcarriers and mapping the second sequence onto M odd-numbered subcarriers in the 2M subcarriers comprises:
performing, by the sending device, a 2M×2M DFT on a sum of the first time domain sequence and the second time domain sequence, and mapping a sequence obtained after the DFT onto the 2M subcarriers, or
performing, by the sending device, a 2M×2M DFT on the first time domain sequence to obtain the third sequence, and mapping the third sequence onto the M even-numbered subcarriers, and performing a 2M×2M DFT on the second time domain sequence to obtain the fourth sequence, and mapping the fourth sequence onto the M odd-numbered subcarriers.

### Claim 6

A signal receiving method, comprising:
receiving, by a receiving device, signals from 2M subcarriers, wherein the 2M subcarriers are subcarriers on a same time domain symbol;
performing, by the receiving device, a fast Fourier transform (FFT) on the signals to obtain a first sequence and a second sequence, wherein the first sequence is carried on M even-numbered subcarriers in the 2M subcarriers, the second sequence is carried on M odd-numbered subcarriers in the 2M subcarriers, the first sequence is one of the third sequence and the fourth sequence, the second sequence is the other of the third sequence and the fourth sequence, and the fourth sequence is a sequence carrying M first information elements; and
performing, by the receiving device, signal processing on a receive signal on M subcarriers that carry the fourth sequence, to obtain the M first information elements, wherein for elements of a first time domain sequence corresponding to the third sequence and a second time domain sequence corresponding to the fourth sequence at a same moment, when a complex factor is taken out, one of the first time domain sequence and the second time domain sequence is an in-phase component, and the other is a quadrature component.

### Claim 7 (depends on 6)

The method according to claim 6, wherein:
the first sequence is the third sequence, and the second sequence is the fourth sequence; and
performing, by the receiving device, signal processing on the receive signal on M subcarriers that carry the fourth sequence, to obtain the M first information elements comprises:
performing, by the receiving device, a second joint transform on the received fourth sequence carried on the M odd-numbered subcarriers, to obtain the received second time domain sequence, wherein the second joint transform is a joint transform of an inverse discrete Fourier transform (IDFT) and a second phase rotation, and
demodulating, by the receiving device, the received second time domain sequence to obtain the M first information elements.

### Claim 8 (depends on 7)

The method according to claim 7, wherein:
the first time domain sequence is a sequence obtained by performing an IDFT on the first sequence; and
second phase rotations corresponding to the M elements are respectively e−j×2tπ/2M, wherein t=0, 1, . . . , M−1.

### Claim 9 (depends on 6)

The method according to claim 6, wherein:
performing, by the receiving device, signal processing on the receive signal on M subcarriers that carry the fourth sequence, to obtain the M first information elements comprises:
extending, by the receiving device, the received fourth sequence to be 2M in length by inserting 0s;
performing a 2M×2M IDFT on an extended received fourth sequence to obtain the received second time domain sequence, wherein the received second time domain sequence is the first M elements of a sequence obtained after the IDFT or opposite numbers of the last M elements of a sequence obtained after the IDFT; and
demodulating the received second time domain sequence to obtain the M first information elements.

### Claim 10 (depends on 9)

The method according to claim 9, wherein after performing, by the receiving device, the fast Fourier transform (FFT) on the signals to obtain the first sequence and the second sequence that are received, the method further comprises:
extending, by the receiving device, the received third sequence to be 2M in length by inserting 0s;
performing a 2M×2M IDFT on an extended received third sequence, wherein the received first time domain sequence is the first M elements of a sequence obtained after the IDFT or the last M elements of a sequence obtained after the IDFT; and
demodulating, by the receiving device, the received first time domain sequence to obtain M second information elements carried by the third sequence.

### Claim 11

A signal sending device, comprising:
a processor configured to:
map a first sequence onto M even-numbered subcarriers in 2M subcarriers, and map a second sequence onto M odd-numbered subcarriers in the 2M subcarriers, wherein the first sequence is one of a third sequence and a fourth sequence, the second sequence is the other of the third sequence and the fourth sequence, the 2M subcarriers are subcarriers on a same time domain symbol, the fourth sequence is a sequence carrying M first information elements, and for elements of a second time domain sequence corresponding to the fourth sequence and a first time domain sequence corresponding to the third sequence at a same moment, when a complex factor is taken out, one of the first time domain sequence and the second time domain sequence is an in-phase component, and the other is a quadrature component, and
transform sequences mapped onto the 2M subcarriers to a time domain to generate transmit signals; and
a transmitter configured to send the transmit signals generated by the processor.

### Claim 12 (depends on 11)

The device according to claim 11, wherein:
the first sequence is the third sequence, and the second sequence is the fourth sequence; and
the processor is further configured to: before mapping the second sequence onto the M odd-numbered subcarriers in the 2M subcarriers, perform a first joint transform on the second time domain sequence to obtain the second sequence, wherein the first joint transform is a joint transform of a first phase rotation and an M×M discrete Fourier transform (DFT).

### Claim 13 (depends on 12)

The device according to claim 12, wherein:
the first time domain sequence is a sequence obtained by performing an inverse discrete Fourier transform (IDFT) on the first sequence; and
to perform the first joint transform on the second time domain sequence to obtain the second sequence, the processor is configured to:
perform corresponding first phase rotations on M elements of the second time domain sequence respectively, and perform an M×M DFT on the rotated second time domain sequence to obtain the second sequence, wherein the first phase rotations corresponding to the M elements are respectively e−j×2tπ/2M, wherein t=0, 1, . . . , M−1.

### Claim 14 (depends on 11)

The device according to claim 11, wherein:
a length of the second time domain sequence is M, the fourth sequence is M odd-numbered elements of a sequence obtained by performing a 2M×2M DFT on an extended sequence of the second time domain sequence, a length of the extended sequence of the second time domain sequence is 2M, and the last M elements of the extended sequence of the second time domain sequence are respectively opposite numbers of M elements of the second time domain sequence; and
a length of the first time domain sequence is M, the third sequence is M even-numbered elements of a sequence obtained by performing a 2M×2M DFT on an extended sequence of the first time domain sequence, a length of the extended sequence of the first time domain sequence is 2M, and the last M elements of the extended sequence of the first time domain sequence are respectively the same as M elements of the second time domain sequence.

### Claim 15 (depends on 14)

The device according to claim 14, wherein:
before mapping the first sequence onto the M even-numbered subcarriers in the 2M subcarriers and mapping the second sequence onto the M odd-numbered subcarriers in the 2M subcarriers, the processor is further configured to:
obtain the first time domain sequence x(k) and the second time domain sequence y(k), and
extend both the first time domain sequence x(k) and the second time domain sequence y(k) into sequences with lengths of 2M, wherein an extension manner of the first time domain sequence is x(k+M)=x(k), wherein k=0, 1, . . . , M−1, and an extension manner of the second time domain sequence is y(k+M)=−y(k), wherein k=0, 1, . . . , M−1; and
to map the first sequence onto the M even-numbered subcarriers in the 2M subcarriers and map the second sequence onto the M odd-numbered subcarriers in the 2M subcarriers, the processor is configured to:
perform a 2M×2M DFT on a sum of the first time domain sequence and the second time domain sequence, and map a sequence obtained after the DFT onto the 2M subcarriers, or
perform a 2M×2M DFT on the first time domain sequence to obtain the third sequence, and map the third sequence onto the M even-numbered subcarriers, and performing a 2M×2M DFT on the second time domain sequence to obtain the fourth sequence, and mapping the fourth sequence onto the M odd-numbered subcarriers.

### Claim 16

A signal receiving device, comprising:
a receiver configured to receive signals from 2M subcarriers, wherein the 2M subcarriers are subcarriers on a same time domain symbol; and
a processor configured to:
perform a fast Fourier transform (FFT) on the signals received by the receiver, to obtain a first sequence and a second sequence that are received, wherein the first sequence is carried on M even-numbered subcarriers in the 2M subcarriers, the second sequence is carried on M odd-numbered subcarriers in the 2M subcarriers, the first sequence is one of the third sequence and the fourth sequence, the second sequence is the other of the third sequence and the fourth sequence, and the fourth sequence is a sequence carrying M first information elements, and
perform signal processing on a receive signal on M subcarriers that carry the fourth sequence, to obtain the M first information elements, wherein for elements of a first time domain sequence corresponding to the third sequence and a second time domain sequence corresponding to the fourth sequence at a same moment, when a complex factor is taken out, one of the first time domain sequence and the second time domain sequence is an in-phase component, and the other is a quadrature component.

### Claim 17 (depends on 16)

The device according to claim 16, wherein:
the first sequence is the third sequence, and the second sequence is the fourth sequence; and
to perform signal processing on the receive signal on the M subcarriers that carry the fourth sequence, to obtain the M first information elements, the processor is configured to:
perform a second joint transform on the received second sequence carried on the M odd-numbered subcarriers, to obtain the received second time domain sequence, wherein the second joint transform is a joint transform of an inverse discrete Fourier transform (IDFT) and a second phase rotation, and
demodulate the received second time domain sequence to obtain the M first information elements.

### Claim 18 (depends on 17)

The device according to claim 17, wherein:
the first time domain sequence is a sequence obtained by performing an IDFT on the first sequence; and
second phase rotations corresponding to the M elements of the first time domain sequence are respectively e−j×2tπ/2M, wherein t=0, 1, . . . , M−1.

### Claim 19 (depends on 16)

The device according to claim 16, wherein to perform signal processing on a receive signal on M subcarriers that carry the fourth sequence, to obtain the M first information elements, the processor is configured to:
extend the received fourth sequence to be 2M in length by inserting 0s;
perform a 2M×2M IDFT on an extended received fourth sequence, wherein the received second time domain sequence is the first M elements of a sequence obtained after the IDFT or opposite numbers of the last M elements of a sequence obtained after the IDFT; and
demodulate the received second time domain sequence to obtain the first information elements.

### Claim 20 (depends on 19)

The device according to claim 19, wherein after performing the fast Fourier transform FFT on the signals to obtain the first sequence and the second sequence that are received, the processor is further configured to:
extend the received third sequence to be 2M in length by inserting 0s;
perform a 2M×2M IDFT on an extended received third sequence, wherein the received first time domain sequence is the first M elements of a sequence obtained after the IDFT or the last M elements of a sequence obtained after the IDFT; and
demodulate the received first time domain sequence to obtain M second information elements carried by the received third sequence.