CDMA communication system using an antenna array

• US 20020085620A1
• Filed: 02/06/2002
• Published: 07/04/2002
• Est. Priority Date: 09/10/1999
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Mesecher, David K.
• Granted Patent: US 6,574,265 B2
• Time in Patent Office: Days
• US Class Current: 375/130
• 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 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels

Abstract

The invention provides for transmission and reception of a data signal using a plurality of transmitting antennas. Each antenna transmits a different reference signal having a pseudo random chip code sequence. A receiver filters each transmitted reference signal using that reference signal'"'"'s chip code. The filtered reference signals are weighted and combined. Each reference signal'"'"'s weight is adaptively adjusted in part on a signal quality of the combined signal. A data signal is transmitted such that different spread spectrum versions of the data signal are transmitted from each transmitting antenna. Each version having a different chip code identifier. Upon reception, each version is filtered with its associated chip code. The filtered versions are weighted in accordance with the adjusted weights associated with the reference signal of the respective antenna.

Claims

1. A method for use in a spread spectrum communication system having a plurality of transmitting antennas, the method comprising:

transmitting from each transmitting antenna, a reference signal having a code uniquely associated with that antenna;

receiving at the receiver all of said transmitted reference signals;

filtering each said transmitted reference signal using that reference signal'"'"'s code;

weighting each said filtered reference signal by a particular weight;

combining said weighted reference signals as a combined signal;

adaptively adjusting each said reference signal'"'"'s particular weight based in part on a signal quality of the combined signal;

transmitting a data signal such that different spread spectrum versions of the data signal are transmitted from each antenna, each version having a different code for the respective transmitting antenna; and

receiving the data signal via filtering each version with its associated code and combining the filtered versions, wherein the different data signal versions are weighted in accordance with the adjusted weights associated with the reference signal of the respective antenna.

2. The method of claim 1 wherein the different data signal versions are weighted in accordance with the adjusted weights prior to transmission.

3. The method of claim 1 wherein the different data signal versions are weighted in accordance with the adjusted weights after reception.

4. The method of claim 1 wherein adaptively adjusting is by using a least mean squared algorithm.

5. The method of claim 1 wherein adaptively adjusting is by using a recursive least squares algorithm.

6. The method of claim 1 wherein adaptively adjusting is by comparing the combined signal with an ideal value to produce an error signal and adjusting each said reference signal'"'"'s particular weight based in part on the error signal.

7. The method of claim 1 wherein the steps of filtering and weighting occur concurrently.