US5910950A
Expired / Lapsed
US
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Demodulator phase correction for code division multiple access receiver
Assignee: Avago Technologies International Sales Pte Ltd
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Filing: 1996-08-16
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Granted: 1999-06-08
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Expires: 2016-08-16
Abstract
Abstract A demodulator of a Code Division Multiple Access Receiver (CDMA) provides single user pilot code aided coherent demodulation of QPSK/CDMA signals using a switch and squarers instead of multipliers. Additionally, a coherent Multicode (MC) CDMA demodulator with a switch for sharing pilot and data correlator results is presented. This change in the demodulators reduces by one-half the number of additions required in the accumulator part for both, the CDMA and the MC-CDMA receiver.
Inventors
- 👤 Stephan ten Brink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:48
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04B1/709
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
102 words
A Code Division Multiple Access, CDMA, receiver comprising means for receiving a coherent CDMA signal including k, where k<or=1, encoded data channels and at least one pilot channel, the k data channels being encoded using mutually orthogonal codes, and a demodulator for decoding a desired one of the k data channels and one of the at least one pilot channels, the demodulator including a switch for switching the desired data channel and the pilot channel to a plurality of accumulator circuits for demodulating the desired data channel the switch being controlled by an orthogonal code of the desired data channel during accumulation.
Claim 2
Dependent Claim
102 words
A Code Division Multiple Access, CDMA, receiver comprising means for receiving a coherent CDMA signal including k, where k<or=1, encoded data channels and at least one pilot channel, the k data channels being encoded using mutually orthogonal codes, and a demodulator for decoding a desired one of the k data channels and one of the at least one pilot channels, the demodulator including a switch for switching the desired data channel and the pilot channel to a plurality of accumulator circuits for demodulating the desired data channel the switch being controlled by an orthogonal code of the desired data channel during accumulation.
Claim 3
Dependent Claim
118 words
A Multi-Code, MC, Code Division Multiple Access, CDMA, receiver comprising means for receiving and despreading a coherent CDMA signal including k, where k>or=to 1, encoded data channels and at least one pilot channel, the k data channels being encoded using mutually orthogonal codes, and a demodulator for decoding a desired set of N data channels out of the k data channels and one of the at least one pilot channels, the demodulator including a switch for switching the desired set of N data channels and the pilot channel to a plurality of accumulator circuits for demodulating a desired data channel, the switch being controlled by an orthogonal code of the desired data of N data channels during accumulation.
Claim 4
Dependent Claim
118 words
A Multi-Code, MC, Code Division Multiple Access, CDMA, receiver comprising means for receiving and despreading a coherent CDMA signal including k, where k>or=to 1, encoded data channels and at least one pilot channel, the k data channels being encoded using mutually orthogonal codes, and a demodulator for decoding a desired set of N data channels out of the k data channels and one of the at least one pilot channels, the demodulator including a switch for switching the desired set of N data channels and the pilot channel to a plurality of accumulator circuits for demodulating a desired data channel, the switch being controlled by an orthogonal code of the desired data of N data channels during accumulation.
Claim 5
Dependent Claim
16 words
The receiving of claim 1 or 2, respectively, wherein the mutually orthogonal codes are Walsh codes.
Claim 6
Dependent Claim
20 words
The CDMA receiver of claim 1 wherein after the accumulator circuits squaring circuits are applied for performing the channel weighting.
Claim 7
Dependent Claim
16 words
The CDMA receiver of claim 4 wherein the squaring circuits are implemented using a look-up table.
Claim 8
Dependent Claim
22 words
The CDMA receiver of claim 4 wherein when the switch is left in a predetermined state, a non-coherent signal energy is determined.
Claim 9
Dependent Claim
23 words
The receiver of claim 1 or 2, respectively, wherein the k data channels include at least a Q and an I signal channel.
Claim 10
Dependent Claim
33 words
The receiver of claim 1 or 2, respectively, being part of a user station of a CDMA or MC-CDMA system, respectively, including at least one base station and a plurality of user stations.
Claim 11
Dependent Claim
33 words
The receiver of claim 1 or 2, respectively, being part of a base station of a CDMA or MC-CDMA system, respectively, including at least one base station and a plurality of user stations.
Claim 12
Dependent Claim
103 words
The MC-CDMA receiver of claim 2 wherein the switch includes a first switch for switching the desired set of N data channels and the at least one pilot channel to a Plurality of accumulator circuits for demodulating the desired set of N data channels, the first switch being controlled by an orthogonal code of the desired set of N data channels during accumulation, a second switch alternately switching intermediate accumulation results to the input of a fast transformation circuitry at N times the symbol rate R b of the data channels and wherein the fast transformation circuitry is optimized to the orthogonal code.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-06-07 | 2002-12-07 | 2003-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-07 | 2006-12-07 | 2007-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-07 | 2010-12-07 | 2011-06-08 | $7700.00 | Window Closed / Lapsed |