High data rate CDMA wireless communication system

• US 6,424,619 B2
• Filed: 01/21/1999
• Issued: 07/23/2002
• Est. Priority Date: 05/28/1996
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Jou, Yu-Cheun, Odenwalder, Joseph P.
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/234,754
• Publication Number:
  US 20010050906A1
• Time in Patent Office: 1,279 Days
• Field of Search: 370/320, 370/335, 370/342, 370/468, 370/208, 370/209, 370/500, 370/328, 370/329, 370/431, 375/130
• US Class Current: 370/209
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 7/264 for data rate control
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence

Abstract

High rate CDMA wireless communication is obtained by forming a set of individually gain adjusted subscriber channels. Each channel has a set of orthogonal subchannel codes having a small number of PN spreading chips per orthogonal waveform period. Preferably, the set of sub-channel codes are comprised of four Walsh codes, each orthogonal to the remaining set and four chips in duration. It is also preferred that pilot data be transmitted via a first transmit channel and power control data transmitted via a second transmit channel. The remaining two transmit channels are used for transmitting non-specified digital data including user data or signaling data, or both. One of the two non-specified transmit channels may be configured for BPSK modulation and the other for QPSK modulation.

Claims

1. A method for receiving a signal transmitted by a subscriber unit to a base station comprising:

filtering in-phase receive samples to produce a filtered in-phase pilot phase reference signal;

filtering quadrature-phase receive samples to produce a filtered quadrature-phase pilot reference signal;

multiplying the in-phase receive samples by a first short Walsh cover having a duration of fewer than sixty-four chips per orthogonal waveform period to produce a first in-phase channel signal;

multiplying the quadrature phase receive samples by the first short Walsh cover to produce a first quadrature phase channel signal;

summing the first in-phase channel signal over the duration of the first short Walsh cover to produce a summed first in-phase channel signal;

summing the first quadrature-phase channel signal over the duration of the first short Walsh cover to produce a summed first quadrature-phase channel signal;

multiplying the filtered in-phase pilot phase reference signal by the summed first in-phase channel signal to produce a first in-phase product;

multiplying the filtered quadrature-phase pilot phase reference signal by the summed first quadrature-phase channel signal to produce a first quadrature-phase product; and

adding the first in-phase product to the first quadrature-phase product to produce a first phase rotated signal.

2. The method of claim 1 wherein the first short Walsh cover has a duration of four chips.

3. The method of claim 1 wherein the first short Walsh cover is +, −

, +, −

.

4. The method of claim 1 wherein the first short Walsh cover is +, +, −

, −

.

5. The method of claim 1 wherein the first short Walsh cover is +, −

, −

, +.

6. The method of claim 1 further comprising:

multiplying the in-phase receive samples by a second short Walsh cover having a duration of fewer than sixty-four chips per orthogonal waveform period, wherein the second short Walsh cover is orthogonal to the first short Walsh cover, to produce a second in-phase channel signal;

multiplying the quadrature phase receive samples by the second short Walsh cover to produce a second quadrature phase channel signal;

summing the second in-phase channel signal over the duration of the second short Walsh cover to produce a summed second in-phase channel signal;

summing the second quadrature-phase channel signal over the duration of the second short Walsh cover to produce a summed second quadrature-phase channel signal;

multiplying the filtered in-phase pilot phase reference signal by the summed second in-phase channel signal to produce a second in-phase product;

multiplying the filtered quadrature-phase pilot phase reference signal by the summed second quadrature-phase channel signal to produce a second quadrature-phase product; and

adding the second in-phase product to the second quadrature-phase product to produce a second phase rotated signal.

7. The method of claim 1 further comprising performing complex multiplication of a downconverted signal by a complex PN code to produce the in-phase receive samples and quadrature-phase receive samples.

8. A base station apparatus comprising:

a first pilot filter configured to filter in-phase receive samples to produce a filtered in-phase pilot phase reference signal;

a second pilot filter configured to filter quadrature-phase receive samples to produce a filtered quadrature-phase pilot reference signal;

a first in-phase multiplier configured to multiply the in-phase receive samples by a first short Walsh cover having a duration of fewer than sixty-four chips per orthogonal waveform period to produce a first in-phase channel signal;

a first quadrature phase multiplier configured to multiply the quadrature phase receive samples by the first short Walsh cover to produce a first quadrature phase channel signal;

a first in-phase summer configured to sum the first in-phase channel signal over the duration of the first short Walsh cover to produce a summed first in-phase channel signal;

a first quadrature-phase summer configured to sum the first quadrature-phase channel signal over the duration of the first short Walsh cover to produce a summed first quadrature-phase channel signal;

a first in-phase multiplier configured to multiply the filtered in-phase pilot phase reference signal by the summed first in-phase channel signal to produce a first in-phase product;

a first quadrature-phase multiplier configured to multiply the filtered quadrature-phase pilot phase reference signal by the summed first quadrature-phase channel signal to produce a first quadrature-phase product; and

a first adder configured to add the first in-phase product to the first quadrature-phase product to produce a first phase rotated signal.

9. The apparatus of claim 8 wherein the first short Walsh cover has a duration of four chips.

10. The apparatus of claim 8 wherein the first short Walsh cover is +, −

, +, −

.

11. The apparatus of claim 8 wherein the first short Walsh cover is +, +, −

, −

.

12. The apparatus of claim 8 wherein the first short Walsh cover is +, −

, −

, +.

13. The apparatus of claim 8 further comprising:

a second in-phase multiplier configured to multiply the in-phase receive samples by a second short Walsh cover having a duration of fewer than sixty-four chips per orthogonal waveform period, wherein the second short Walsh cover is orthogonal to the second Walsh cover, to produce a second in-phase channel signal;

a second quadrature phase multiplier configured to multiply the quadrature phase receive samples by the second short Walsh cover to produce a second quadrature phase channel signal;

a second in-phase summer configured to sum the second in-phase channel signal over the duration of the second short Walsh cover to produce a summed second in-phase channel signal;

a second quadrature-phase summer configured to sum the second quadrature-phase channel signal over the duration of the second short Walsh cover to produce a summed second quadrature-phase channel signal;

a second in-phase multiplier configured to multiply the filtered in-phase pilot phase reference signal by the summed second in-phase channel signal to produce a second in-phase product;

a second quadrature-phase multiplier configured to multiply the filtered quadrature-phase pilot phase reference signal by the summed second quadrature-phase channel signal to produce a second quadrature-phase product; and

a second adder configured to add the second in-phase product to the second quadrature-phase product to produce a second phase rotated signal.

14. The apparatus of claim 8 further comprising a complex PN despreader configured to perform complex multiplication of a downconverted signal by a complex PN code to produce the in-phase receive samples and quadrature-phase receive samples.