Out-of-band emission cancellation

• US 9,240,910 B2
• Filed: 10/14/2010
• Issued: 01/19/2016
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Original Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Inventors: Huang, Xiaojing, Guo, Yingjie Jay
• Primary Examiner(s): NGUYEN, LEON VIET Q
• Application Number:
  US13/504,456
• Publication Number:
  US 20120269286A1
• Time in Patent Office: 1,923 Days
• Field of Search: 375/260, 375/268, 375/284, 375/295, 375/296, 375/340, 455/69, 455/114.2, 455/109, 455/502, 455/522
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 25/0248 Eigen-space methods
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/26265 Arrangements for sidelobes suppression specially adapted to multicarrier systems, e.g. spectral precoding
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT

Abstract

A transmission signal pre-processing method and apparatus for out-of-band emission cancellation are disclosed. For each of N subchannels in a band weighting each of N subchannel symbols by a calculated value in the range from 0 to 1 is performed. Precoding said N weighted symbols, organised as an N×1 matrix, by multiplication by a unitary matrix is then performed.

Claims

1. A transmission signal pre-processing method for out-of-band emission cancellation performed within a transmitter, the method comprising the steps of:

weighting each of N subchannel symbols in a band by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power;

precoding said N weighed symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix;

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction term; and

wherein said identity matrix (I_N) and said correction term are of the form;

2. A method of claim 1, performed in an Orthogonal Frequency Division Multiplexing (OFDM) scheme.

3. A method according to claim 1, wherein said identity matrix and said correction expression are the subject of single value decomposition to give said diagonal matrix and said unitary matrix.

4. A transmission signal pre-processing method for out-of-band emission cancellation performed within a transmitter, the method comprising the steps of:

weighting each of N subchannel symbols in a band by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power;

precoding said N weighed symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix;

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction term; and

wherein said identity matrix and said correction term are of the form;

5. An out-of-band emission cancellation method performed within a transmitter comprising the steps of:

performing mapping of input data bits into time domain data symbols;

converting said time domain symbols into a plurality of subchannels;

for each of N subchannels in a band;

weighting each of N subchannel symbols by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power; and

precoding said N weighted symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix;

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction expression; and

wherein said identity matrix (I_N) and said correction expression are of the form;

6. A method according to claim 5, performed in an Orthogonal Frequency Division Multiplexing (OFDM) scheme.

7. A method according to claim 5, wherein said identity matrix and said correction expression are the subject of single value decomposition to give said diagonal matrix and said unitary matrix.

8. An out-of-band emission cancellation method performed within a transmitter comprising the steps of:

performing mapping of input data bits into time domain data symbols;

converting said time domain symbols into a plurality of subchannels;

for each of N subchannels in a band;

weighting each of N subchannel symbols by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power; and

precoding said N weighted symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix.

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction term;

wherein said identity matrix and said correction term are of the form;

9. A transmitter comprising:

a module performing mapping of input data bits into time domain data symbols;

a module converting said time domain symbols into a plurality of subchannels;

for each of N subchannels in a band;

a module weighting each of N subchannel symbols by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power; and

a module precoding said N weighted symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix;

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction term;

wherein said identity matrix (I_N) and said correction term are of the form;

10. A transmitter according to claim 9, wherein said transforming module is an inverse fast Fourier transform circuit.

11. A transmitter according to claim 9, wherein said identity matrix and said correction expression are the subject of single value decomposition to give said diagonal matrix and said unitary matrix.

12. A transmitter comprising:

a module performing mapping of input data bits into time domain data symbols;

a module converting said time domain symbols into a plurality of subchannels;

for each of N subchannels in a band;

a module weighting each of N subchannel symbols by a calculated value in the range from 0 to 1, wherein weighting by the value 0 cancels the subchannel symbol and weighting by the value 1 results in the subchannel symbol being transmitted at full power; and

a module precoding said N weighted symbols by multiplication by a unitary matrix;

wherein said N subchannel symbols are organized as a N×

1 symbols matrix and said calculated values are organized in a N×

N diagonal matrix, and said weighting is performed by multiplying the symbols matrix and the diagonal matrix;

wherein said diagonal matrix and said unitary matrix are determined from an identity matrix of order N and a correction term;

wherein said identity matrix and said correction term are of the form;