Apparatus And Method For Identification And Compensation Of Distortion In A Multi-Antenna System

• US 20180167092A1
• Filed: 05/17/2016
• Published: 06/14/2018
• Est. Priority Date: 05/17/2016
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: HAUSMAIR, Katharina, ERIKSSON, Thomas, FAGER, Christian, GUSTAVSSON, Ulf
• Granted Patent: US 10,153,793 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 2001/0425 with linearisation using predistortion
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

The disclosure relates to devices, methods, and computer programs in mobile communications in order to reduce signal distortions. Specifically, it relates to a transmitter system which comprises a plurality of signal paths. Each signal path is associated with an input transmission signal. Each signal path comprises an analogue portion of the signal path. Each 5 signal path comprises a Dual-Input Digital Predistortion, DI DPD, module. The DI DPD is configured to provide a predistorted input transmission signal to the analogue portion in response to a received Crosstalk and Mismatch, CTM, signal and the input transmission signal. The transmitter system further comprises one or more CTM modules configured to receive one or more input transmission signals. The CTM module comprises to separately generate for 10 each DI DPD module the CTM signal, where said CTM signals represent CTM distortions caused by one or more output transmission signals of each said analogue portion.

Claims

1-31. -31. (canceled)

32. A transmitter system for transmitting input transmission signals on respective antenna ports, the transmitter system comprising:

a plurality of signal paths, each signal path comprising;

an input node for receiving an input transmission signal;

an analog portion of the signal path connected to an antenna port, the antenna port associated with a multi-antenna array;

a Dual-Input Digital Predistortion (DI DPD) module coupled to the input node and the analog portion of the signal path, the DI DPD configured to provide a predistorted input transmission signal to the analog portion of the signal path in response to a received Crosstalk and Mismatch (CTM) signal and the input transmission signal; and

one or more CTM modules configured to;

receive one or more input transmission signals;

separately generate, for each DI DPD module, the CTM signal,

the CTM signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path.

33. The transmitter system of claim 32, wherein:

the CTM distortions for each signal path are caused by one or more portions of one or more output transmission signals at an output of each the analog portion of the signal path;

each CTM signal is generated in response to all input transmission signals and a representative model of the CTM distortions.

34. The transmitter system of claim 32, wherein the CTM distortions for each signal path are caused by one or more antenna crosstalks between respective output transmission signals and one or more other output transmission signals and/or circuitry mismatches at the output of respective analog portion of the signal path.

35. The transmitter system of claim 32, wherein the CTM module is configured to separately generate the CTM signals for each DI DPD module based upon a linear system having the input transmission signals as input parameters.

36. The transmitter system of claim 32, wherein the CTM module is configured to separately generate the CTM signals for each DI DPD module based upon S-parameters of the multi-antenna array.

37. The transmitter system of claim 32, wherein the CTM module is configured to separately generate the CTM signals for each DI DPD module based upon linear filter functions.

38. The transmitter system of claim 32, wherein the CTM module is configured to comprise a plurality of periodically updated CTM coefficients, the CTM coefficients being applied to separately generate the CTM signals for each DI DPD module.

39. The transmitter system of claim 38, wherein the plurality of periodically updated CTM coefficients are forwarded from a CTM identification module where the CTM coefficients are identified in response to each of the predistorted input transmission signals provided by each of the DI DPD modules and each of the output transmission signals at the output of the analog portion of the signal path.

40. The transmitter system of claim 32, wherein each of the DI DPD modules is configured to predistort the input transmission signal based on one or more entries in a DI DPD Look Up Table (LUT) stored in the respective DI DPD module, wherein the one or more entries are selected in response to the individual CTM signal and the input transmission signal.

41. The transmitter system of claim 32, wherein each of the DI DPD modules is configured to predistort the input transmission signal based on a DI DPD transfer function.

42. The transmitter system of claim 40, wherein each signal path further comprise a DI DPD identification module configured to periodically update entries of each DI DPD LUT of each DI DPD module in response to each of the predistorted input transmission signals provided by each of the DI DPD modules and each of the output transmission signals at the output of the analog portion of the signal path.

43. The transmitter system of claim 42, wherein each DI DPD identification module is further configured to periodically update the entries of the DI DPD LUT in response to each of the CTM signals.

44. The transmitter system of claim 41, wherein the DI DPD transfer function comprises one or more of:

a Volterra series-based bivariate polynomial;

a neural network predistorter; and

/or

a radial-basis function-based predistorter.

45. The transmitter system of claim 32, wherein each antenna port comprises an antenna element.

46. The transmitter system of claim 32, wherein the analog portions of the signal paths comprises one or more of:

a radio frequency digital analog converter;

a power amplifier;

a mixer;

a filter;

Digital Up Converter;

a local oscillator; and

a matching network.

47. A radio network node, comprising:

a baseband module;

one or more transmitter systems, each transmitter system for transmitting input transmission signals on respective antenna ports, each transmitter system comprising;

a plurality of signal paths, each signal path comprising;

an input node for receiving an input transmission signal;

an analog portion of the signal path connected to an antenna port, the antenna port associated with a multi-antenna array;

a Dual-Input Digital Predistortion (DI DPD) module coupled to the input node and the analog portion of the signal path, the DI DPD configured to provide a predistorted input transmission signal to the analog portion of the signal path in response to a received Crosstalk and Mismatch (CTM) signal and the input transmission signal; and

one or more CTM modules configured to;

receive one or more input transmission signals;

separately generate, for each DI DPD module, the CTM signal,

the CTM signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path.

48. A wireless communication device, comprising

a baseband module;

one or more transmitter systems, each transmitter system for transmitting input transmission signals on respective antenna ports, each transmitter system comprising;

a plurality of signal paths, each signal path comprising;

an input node for receiving an input transmission signal;

an analog portion of the signal path connected to an antenna port, the antenna port associated with a multi-antenna array;

a Dual-Input Digital Predistortion (DI DPD) module coupled to the input node and the analog portion of the signal path, the DI DPD configured to provide a predistorted input transmission signal to the analog portion of the signal path in response to a received Crosstalk and Mismatch (CTM) signal and the input transmission signal; and

one or more CTM modules configured to;

receive one or more input transmission signals;

separately generate, for each DI DPD module, the CTM signal,

the CTM signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path.

49. A method for identification and compensation of distortion, caused in a plurality of signal paths, each signal path comprising an analog portion of the signal path, the method comprising:

providing a plurality of input transmission signals;

generating a plurality of Crosstalk and Mismatch (CTM) signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path;

predistorting each of the input transmission signals in response to the respective input transmission signal and the respective CTM signal;

applying each of the predistorted input transmission signals to a respective one of the analog portion of the signal path to provide a plurality of output transmission signals at an output of each the analog portion of the signal path.

50. The method of claim 49, further comprising:

providing a representative model of CTM distortions, wherein the CTM distortions for each signal path are caused by one or more portions of one or more of a plurality of output transmission signals at an output of each the analog portion of the signal path; and

wherein the generating the plurality of CTM signals is in response to the representative model of CTM distortions and all input transmission signals.

51. The method of claim 49, wherein the CTM distortions for each signal path are caused by one or more antenna crosstalks between respective output transmission signals and one or more other output transmission signals and/or circuitry mismatches at the output of respective analog portion of the signal path.

52. The method of claim 50, further comprising providing a linear system as a representative model of the CTM distortions.

53. The method of claim 50, further comprising providing S-parameters of a multi-antenna array connected to the analog portions of the signal paths, as being comprised in the representative model of the CTM distortions.

54. The method of claim 50, further comprising providing linear filter functions, as being comprised in the representative model of the CTM distortions.

55. The method of claim 50:

wherein the model of CTM distortions comprises CTM coefficients; and

further comprising updating CTM coefficients periodically.

56. The method of claim 55, wherein the updating comprises updating the CTM coefficients in response to each of the predistorted input transmission signals and each of the output transmission signals at the output of the analog portions of the signal paths.

57. The method of claim 49, further comprising providing a Dual-Input Digital Predistortion (DI DPD) transfer function;

wherein the predistorting of the input transmission signal is based on the DI DPD transfer function utilizing one or more of;

a Volterra series-based bivariate polynomial;

a look up table;

a neural network predistorter; and

/or

a radial-basis function-based predistorter.

58. The method of claim 49:

further comprising providing a Dual-Input Digital Predistortion (DI DPD) Look Up Table (LUT);

wherein the predistorting of the input transmission signal is based on one or more entries in the DI DPD LUT, wherein the one or more entries are selected in response to the individual CTM signal and the input transmission signal.

59. The method claim 57, wherein the predistorting comprises updating DI DPD coefficients of the DI DPD transfer function periodically in response to each of the predistorted input transmission signals and each of the output transmission signals at the output of the analog portion of the signal path.

60. The method of claim 59, wherein the updating comprises updating the DI DPD coefficients periodically in response to each of the CTM signals.

61. A non-transitory computer readable recording medium storing a computer program product for controlling identification and compensation of distortion, caused in a plurality of signal paths, each signal path comprising an analog portion of the signal path, the computer program product comprising software instructions which, when run on processing circuitry of a communications device, causes the communications device to:

provide a plurality of input transmission signals;

generate a plurality of Crosstalk and Mismatch (CTM) signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path;

predistort each of the input transmission signals in response to the respective input transmission signal and the respective CTM signal;

apply each of the predistorted input transmission signals to a respective one of the analog portion of the signal path to provide a plurality of output transmission signals at an output of each the analog portion of the signal path.

62. A predistortion device for identification and compensation of distortion, caused in a plurality of signal paths, each signal path comprising an analog portion of the signal path, the predistortion device comprising:

processing circuitry, the processing circuitry configured to;

provide a plurality of input transmission signals;

generate a plurality of Crosstalk and Mismatch (CTM) signals representing CTM distortions caused by one or more output transmission signals of each the analog portion of the signal path;

predistort each of the input transmission signals in response to the respective input transmission signal and the respective CTM signal;

apply each of the predistorted input transmission signals to a respective one of the analog portion of the signal path.