Receiving station with interference signal suppression

• US 6,725,028 B2
• Filed: 05/30/2001
• Issued: 04/20/2004
• Est. Priority Date: 06/14/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter, Bonaccorso, Mario, Ling, Fuyun, Sindhushayana, Nagabhushana
• Primary Examiner(s): TRAN, CONGVAN
• Application Number:
  US09/870,958
• Publication Number:
  US 20010053678A1
• Time in Patent Office: 1,056 Days
• Field of Search: 455/137, 455/296, 455/132, 455/139, 455/140, 455/151.11, 455/161.2, 455/292.1, 455/292.2, 455/293.1, 455/295.1, 455/271, 455/272, 455/273, 455/63.1, 455/114.2, 455/114.3, 455/278.1, 375/147, 375/144, 375/148, 375/346, 375/348, 375/349, 375/316
• US Class Current: 455/296
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

An optimum combiner that reduces the amount of interference imposed upon a first base station by transmissions of other base stations within the same communication system. Two antennas are used to receive transmissions within a receiving station. A rake receiver is coupled to each antenna. By optimally combining the signals that are received by each independent finger of the rake receiver, interference that is correlated between a finger associated with the first antenna and a finger associated with the second antenna can be minimized with respect to the desired signal. Optimum combining requires determination of optimum combining coefficients.

Claims

1. In a wireless communication receiver, the method comprising:

receiving a plurality of signals at the receiver;

sampling the plurality of signals to generate sampled signals to the receiver;

determining weights for the plurality of signals, comprising;

estimating an autocorrelation of the sampled signals;

estimating a cross correlation between the sampled signals and corresponding transmitted signals; and

calculating the weights as a product of the autocorrelation and the cross correlation;

receiving data signals at the receiver, the data signals having corresponding transmitted data signals; and

applying the weights to the data signals to generate an estimate of the transmitted data signals.

2. The method as in claim 1, wherein the cross correlation is a function of fading coefficients.

3. The method as in claim 1, further comprising:

rotating the phase of the sampled signal.

4. The method as in claim 1, wherein the plurality of signals received at the receiver includes information known a priori by the receiver.

5. The method as in claim 4, wherein the information corresponds to a pilot sequence.

6. In a wireless communication receiver, the method comprising:

receiving a plurality of signals at the receiver;

sampling the plurality of signals to generate sampled signals to the receiver;

determining weights for the plurality of signals, comprising;

estimating an autocorrelation of the noise received at the receiver;

estimating a cross correlation between the sampled signals and corresponding transmitted signals; and

calculating the weights as a product of the autocorrelation and the cross correlation;

receiving data signals at the receiver, the data signals having corresponding transmitted data signals; and

applying the weights to the data signals to generate an estimate of the transmitted data signals.

7. The method as in claim 6, wherein the cross correlation is a function of fading coefficients.

8. The method as in claim 7, wherein the receiver includes a rake type receiver having a plurality of fingers, further comprising:

estimating the fading coefficients per each finger of the plurality of fingers of the rake type receiver.

9. A wireless receiver apparatus, comprising:

receiver means for processing a plurality of signal paths;

sampling means for sampling a plurality of signals to generate sampled signals;

weight calculation means for calculating weights for the plurality of signals, comprising;

first estimation means for estimating an autocorrelation of the sampled signals;

second estimation means for estimating a cross correlation between the sampled signals and corresponding transmitted signals; and

weight processing means for calculating the weights as a product of the autocorrelation and the cross correlation; and

weighting means for applying the weights to data signals received at the apparatus and for generating an estimate of corresponding transmitted data signals.

10. The wireless receiver apparatus of claim 9, wherein the first estimation means calculates the autocorrelation as $R_{\mathrm{yy}}=\frac{1}{M}$

∑

m=1M

y

(m)

yH

(m),

wherein y(m) is a sampled signal, and M is a total number of samples.

11. The wireless receiver apparatus of claim 9, wherein the second estimation means calculates the cross correlation as: