SCALING USING GAIN FACTORS FOR USE IN DATA DETECTION

• US 20090316762A1
• Filed: 08/28/2009
• Published: 12/24/2009
• Est. Priority Date: 07/18/2002
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Pan, Jung-Lin, Kim, Younglok, Grieco, Donald
• Granted Patent: US 8,189,648 B2
• Time in Patent Office: Days
• US Class Current: 375/148
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 1/71055 using minimum mean squared error [MMSE] detector
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference

Abstract

Data is estimated from a received vector comprising a plurality of communications. A received wireless signal is converted to a baseband signal, which is sampled to produce a received vector. Channel responses are estimated for the received communications. The noise variance is estimated. The noise variance is scaled by a scaling factor. Samples are processed using the estimated channel responses and the scaled noise variance to produce a spread data vector. The spread data vector is despread to recover the data of the received wireless signal.

Claims

1. A method for recovering data from a plurality of communication signals transmitted in code division multiple access communication, the method comprising:

receiving the communication signals;

sampling the received communication signals to produce a received vector;

estimating a channel response matrix and a noise variance based on the received vector;

scaling the channel response matrix or the noise variance based on a code power scaling factor, wherein the code power scaling factor is based on a gain of at least one of the received communication signals;

equalizing the received communication signals based on the scaled channel response matrix or noise variance to produce a spread data vector;

despreading the spread data vector; and

recovering data from the received communication signals based on the despread spread data vector.

2. The method of claim 1, further comprising:

scaling the spread data vector;

despreading the scaled data vector; and

recovering data from the received communication signals based on the despread scaled data vector.

3. The method of claim 1, wherein the code power scaling factor is based on the gain of at least on selected communication signal.

4. The method of claim 1, wherein the code power scaling factor is based on the gains of all of the received communication signals.

5. The method of claim 1, wherein the code power scaling factor is based on the gain of a selected coded composite transport channel.

6. The method of claim 1, wherein the detecting data based on the despaired data vector utilizes a multiuser detection device.

7. A wireless spread spectrum user equipment comprising:

an antenna for receiving a plurality of communication signals, the communication signals transmitted in a shared spectrum;

a sampling device for producing a received vector;

a channel estimation device for estimating a channel response matrix of the received communication signals;

a scaling device for scaling the channel response matrix or a noise variance based on a code power scaling factor, wherein the code power scaling factor is based on the gain of at least one received communication signal;

a channel equalizer for equalizing the channel response based on the received vector and the scaled channel response matrix or scaled noise variance and producing a spread data vector; and

a data estimation device for recovering data from the received communication signals based on the spread data vector.

8. The user equipment of claim 7, wherein the data estimation device comprises a multiuser detection device.

9. The user equipment of claim 7, wherein the data estimation device comprises a despreader to despread the spread data vector.

10. The user equipment of claim 9, further comprising:

a second scaling device for scaling the spread data vector, wherein the spread data vector is scaled by a scaling factor derived from at least one gain factor.

11. The user equipment of claim 7, wherein the at least one gain factor is a gain factor of a selected communication signal.

12. The user equipment of claim 7, wherein the scaling factor is derived from gain factors from all of the received communication signals.

13. The user equipment of claim 7, wherein the scaling factor is derived from gain factors from a selected coded composite transport channel.

14. A wireless spread spectrum base station comprising:

an antenna for receiving a plurality of communication signals, the communication signals transmitted in a shared spectrum;

a sampling device for producing a received vector;

a channel estimation device for estimating a channel response matrix of the received communication signals;

a scaling device for scaling the channel response matrix or a noise variance based on a code power scaling factor, wherein the code power scaling factor is based on the gain of at least one received communication signal;

a channel equalizer for equalizing the channel response based on the received vector and the scaled channel response matrix or scaled noise variance and producing a spread data vector; and

a data estimation device configured to recover data from the received communication signals based on the spread data vector.

15. The base station of claim 14, wherein the data estimation device comprises a multiuser detection device.

16. The base station of claim 14, wherein the data estimation device comprises a despreader to despread the spread data vector.

17. The base station of claim 16, further comprising:

a second scaling device for scaling the spread data vector, wherein, the spread data vector is scaled by a scaling factor derived from at least one gain factor.

18. The base station of claim 14, wherein the at least one gain factor is a gain factor of a selected communication signal.

19. The base station of claim 14, wherein the scaling factor is derived from gain factors from all of the received communication signals.

20. The base station of claim 14, wherein the scaling factor is derived from gain factors from a selected coded composite transport channel.