Method and apparatus to adjust received signal

• US 8,711,760 B2
• Filed: 03/26/2010
• Issued: 04/29/2014
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Kasher, Assaf
• Primary Examiner(s): Moore, Ian N
• Assistant Examiner(s): Huynh, Dung B
• Application Number:
  US12/732,459
• Publication Number:
  US 20110235622A1
• Time in Patent Office: 1,495 Days
• Field of Search: None
• US Class Current: 370/317
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 25/03891 Spatial equalizers MIMO diversity systems H04B7/0413
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo

Abstract

A wireless communication device, a wireless communication system and a method to adjust transmitted signals constellation in a maximum likelihood multiple-input-multiple-output receiver by transmitting an EVM deviation value. The EVM deviation value may be added to a pre-stored error value at the receiver.

Claims

1. A method comprising:

estimating at a multiple-input-multiple-output (MIMO) transmitter a transmission noise level of said MIMO transmitter;

calculating at said MIMO transmitter an error vector magnitude (EVM) deviation value by comparing the estimated transmission noise level of said MIMO transmitter to stored noise values; and

transmitting a frame from said MIMO transmitter, wherein the frame includes a field including said EVM deviation value, said EVM deviation value indicating a quality of the estimated transmission noise level of said MIMO transmitter in relation to a predefined noise level for a transmitted constellation of data streams.

2. The method of claim 1 comprising measuring the noise level of said transmitter prior to a transmission by said MIMO transmitter.

3. A method of adjusting a received signal in a multiple-input-multiple-output receivers system, the method comprising:

receiving from a transmitter a deviation of an error vector magnitude (EVM) value with a received data stream, the EVM deviation value indicating a quality of a transmission noise level of said transmitter in relation to a predefined noise level;

detecting a symbol from the received data stream using a maximum likelihood detection scheme;

adding the deviation EVM value to a pre-stored EVM value; and

placing the symbol on a constellation point, based on a result of said adding.

4. The method of claim 3, wherein receiving comprises:

receiving a frame that includes the deviation EVM value.

5. The method of claim 3 comprising:

receiving a modulation coding scheme and adding the EVM deviation value to the pre-stored EVM value according to the modulation coding scheme.

6. The method of claim 3 comprising:

adjusting the received signal for transmitter noise by adding the deviation EVM value to a pre-stored EVM value in order to place the symbol on a constellation point.

7. A wireless communication device comprising:

a multiple-input-multiple-output (MIMO) receivers system to receive from a MIMO transmitter a deviation of an error vector magnitude (EVM) value with a received data stream, the EVM deviation value indicating a quality of a transmitter noise of said MIMO transmitter in relation to a predefined noise level;

a memory to store in a table a pre-stored EVM value; and

a detector to detect a symbol from the received data stream using a maximum likelihood detection scheme, to adjust a received signal for the transmitter noise of said MIMO transmitter by adding the deviation EVM value to the pre-stored EVM value and to place the symbol on a constellation point.

8. The wireless communication device of claim 7, wherein the MIMO receivers system is able to receive a frame that includes the deviation EVM value.

9. The wireless communication device of claim 8, wherein the frame includes a modulation coding scheme and the detector is able to add the EVM deviation value to the pre-stored EVM value according to the modulation coding scheme.

10. The wireless communication device of claim 7, wherein the detector comprises a maximum likelihood detector.

11. A multiple-input-multiple-output (MIMO) transmitter comprising:

a noise estimator to estimate a transmission noise level of said MIMO transmitter; and

an error vector magnitude (EVM) deviation value generator to calculate an EVM deviation value by comparing the estimated transmission noise level of said MIMO transmitter to stored noise values;

said MIMO transmitter to transmit a frame comprising a field including said EVM deviation value, said EVM deviation value indicating a quality of the estimated transmission noise level of said MIMO transmitter in relation to a predefined noise level for a transmitted constellation of data streams.

12. The MIMO transmitter of claim 11, wherein said noise estimator is to measure the transmission noise level of said MIMO transmitter prior to a transmission by said MIMO transmitter.

13. A wireless communication system comprising:

an antenna array operably coupled to a multiple-input-multiple-output (MIMO) receivers system to receive from a MIMO transmitter a deviation of an error vector magnitude (EVM) value with a received data stream, the EVM deviation value indicating a quality of a transmitter noise of said MIMO transmitter in relation to a predefined noise level; and

a detector to detect a symbol from the received data stream using a maximum likelihood detection scheme, and to add the deviation EVM value to a pre-stored EVM value in order to place the symbol on a constellation point.

14. The wireless communication system of claim 13, wherein the MIMO receiver system is able to receive a frame that includes the deviation EVM value.

15. The wireless communication system of claim 14, wherein the frame includes a modulation coding scheme and the detector is able to add the EVM deviation value to the pre-stored EVM value according to the modulation coding scheme.

16. The wireless communication system of claim 14 comprising:

a memory to store in a table the pre stored EVM value,

wherein the detector is able to adjust a received signal for said transmitter noise by adding the deviation EVM value to the pre-stored EVM value from the table in order to place the symbol on the constellation point.

17. The wireless communication system of claim 13, wherein the detector comprises a maximum likelihood detector.

18. The wireless communication system of claim 13, wherein the transmitter noise comprises white noise.

19. The wireless communication system of claim 13, wherein said wireless communication system is able to operate within a wireless local area network using Orthogonal Frequency-Division Multiplexing (OFDM) scheme.