METHOD AND DEVICE FOR REDUCING INTERMODULATION INTERFERENCE

• US 20160301436A1
• Filed: 06/16/2016
• Published: 10/13/2016
• Est. Priority Date: 12/17/2013
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zou, Zhiqiang, Qiao, Hui, Chai, Honglin
• Granted Patent: US 10,305,524 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

Embodiments of the present invention provide a method and a device for reducing intermodulation interference. The method includes: performing real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal; and cancelling, according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal, where M is an integer greater than or equal to 2, and the M downlink transmit signals are baseband signals that are transmitted on M carriers and that are not combined. Based on the foregoing solutions, the actually generated intermodulation interference can be effectively cancelled, thereby reducing intermodulation interference and improving system performance.

Claims

1. A method for reducing intermodulation interference, the method comprising:

performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal; and

cancelling, by the base station, according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal, wherein M is an integer greater than or equal to 2, and the M downlink transmit signals are M baseband signals that are transmitted on M carriers and that are not combined.

2. The method according to claim 1, wherein performing, by abase station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal comprises:

acquiring, by the base station, M sampling points that respectively correspond to the M downlink transmit signals at a first moment;

determining, by the base station, a component element set according to the M sampling points, wherein component elements comprised in the component element set are conjugates of the M sampling points and the M sampling points;

determining, by the base station, according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements and N is a positive integer;

determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and

obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components.

3. The method according to claim 1, wherein performing, by a base station, real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal comprises:

acquiring, by the base station, T delay items, wherein the delay item indicates a sampling value of a downlink transmit signal after a delay at a first moment, wherein T is a positive integer;

determining, by the base station, a component element set according to the T delay items, wherein component elements comprised in the component element set are conjugates of the T delay items and the T delay items;

determining, by the base station, according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements;

determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and

obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components.

4. The method according to claim 2, wherein:

determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components comprises;

performing, by the base station, elimination on a matrix [A Y] to obtain a matrix [A′

Y′

], wherein components in the matrix Y′

are the N coefficients, wherein

5. The method according to claim 2, wherein before obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components, the method further comprises:

performing, by the base station, time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal.

6. The method according to claim 5, wherein performing, by the base station, time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal comprises:

determining, by the base station, according to

7. The method according to claim 3, wherein:

determining, by the base station, according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components comprises;

performing, by the base station, elimination on a matrix [A Y] to obtain a matrix [A′

Y′

], wherein components in the matrix Y′

are the N coefficients, wherein

8. The method according to claim 3, wherein before obtaining, by the base station, the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components, the method further comprises:

performing, by the base station, time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal.

9. The method according to claim 8, wherein performing, by the base station, time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal comprises:

determining, by the base station, according to

10. The method according to claim 1, wherein cancelling, by the base station according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal comprises:

when the first intermodulation interference signal meets a cancellation condition, cancelling, by the base station, the intermodulation interference in the uplink receive signal by using the first intermodulation interference signal, wherein the cancellation condition comprises at least one of the following;

an amplitude of the first intermodulation interference signal is greater than a first threshold, a frequency of the first intermodulation interference signal falls within a frequency band range of the uplink receive signal, and a fluctuation range of the first intermodulation interference signal is less than a second threshold.

11. A device, comprising:

a processor coupled to a memory by using a bus system, wherein the memory includes computer-executable instructions which when executed by the processor cause the device to;

perform real-time estimation according to time domain information of M downlink transmit signals, to obtain a first intermodulation interference signal; and

cancel, according to the first intermodulation interference signal, intermodulation interference generated by the M downlink transmit signals in an uplink receive signal, wherein M is an integer greater than or equal to 2, and the M downlink transmit signals are M baseband signals that are transmitted on M carriers and that are not combined.

12. The device according to claim 11, wherein the computer-executable instructions which when executed by the processor further cause the device to:

acquire M sampling points that respectively correspond to the M downlink transmit signals at a first moment;

determine a component element set according to the M sampling points, wherein component elements comprised in the component element set are conjugates of the M sampling points and the M sampling points;

determine according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements and N is a positive integer;

determine according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and

obtain the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components.

13. The device according to claim 11, wherein the computer-executable instructions which when executed by the processor further cause the device to:

acquire T delay items, wherein the delay item indicates a sampling value of a downlink transmit signal after a delay at a first moment, wherein T is a positive integer;

determine component element set according to the T delay items, wherein component elements comprised in the component element set are conjugates of the T delay items and the T delay items;

determine according to the component element set, N intermodulation components in a multinomial for estimating the first intermodulation interference signal, wherein the intermodulation component is a product of at least two component elements;

determine according to the N intermodulation components and the uplink receive signal, N coefficients that respectively correspond to the N intermodulation components; and

obtain the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components.

14. The device according to claim 12, wherein the computer-executable instructions which when executed by the processor further cause the device to:

perform elimination on a matrix [A Y] to obtain a matrix [A′

Y′

], wherein components in the matrix Y′

are the N coefficients, wherein

15. The device according to claim 12, wherein the computer-executable instructions which when executed by the processor further cause the device to:

before obtaining the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components, perform time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal.

16. The device according to claim 15, wherein the computer-executable instructions which when executed by the processor further cause the device to:

determine according to

17. The method according to claim 13, wherein the computer-executable instructions which when executed by the processor further cause the device to:

perform, by the base station, elimination on a matrix [A Y] to obtain a matrix [A′

Y′

], wherein components in the matrix Y′

are the N coefficients, wherein

18. The device according to claim 13, wherein the computer-executable instructions which when executed by the processor further cause the device to:

before the obtaining the first intermodulation interference signal according to a multinomial comprising the N intermodulation components and the coefficients corresponding to the N intermodulation components, perform time alignment on the uplink receive signal and the M downlink transmit signals according to the N intermodulation components and the uplink receive signal.

19. The device according to claim 18, wherein the computer-executable instructions which when executed by the processor further cause the device to:

determine according to

20. The device according to claim 11, wherein the computer-executable instructions which when executed by the processor further cause the device to:

when the first intermodulation interference signal meets a cancellation condition, cancel the intermodulation interference in the uplink receive signal by using the first intermodulation interference signal, wherein the cancellation condition comprises at least one of the following;

an amplitude of the first intermodulation interference signal is greater than a first threshold, a frequency of the first intermodulation interference signal falls within a frequency band range of the uplink receive signal, and a fluctuation range of the first intermodulation interference signal is less than a second threshold.