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EP0493904A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method and apparatus for reducing effects of multiple access interference in a radio receiver in a code division multiple access communication system

Assignee: AT&T Inc
•
Filing: 1991-12-10
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Granted: —
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Expires: 2011-12-10
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Abstract

Abstract A CDMA system is disclosed which reduces the effects of multiple access interference, thus increasing channel capacity and achieving greater efficiency in the use of a given frequency bandwidth. The signal is received (701) and the codes for the various channels are applied in the usual way to detect the signals in each channel (702-703). The detected signals are then divided (711) into those with a high confidence level ( g l - g m ) and those with a low confidence level ( u l - u k ). The high-confidence signals are then recoded (721-722) and subtracted (727) from the received signal. The codes corresponding to the channels whose detected signals had a low confidence level are then applied (731-733) to the resulting signal to derive improved detected signals for those channels.

Inventors

  • 👤 Qi Bi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 18:13
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B1/00; H04B1/69; H04B1/707

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 136 words
Apparatus for reception of radio signals in a CDMA spread spectrum radio transmission system, comprising: means for receiving radio signals comprising a plurality of radio channels encoded by CDMA spread spectrum techniques; CHARACTERIZED BY means for despreading each radio signal in each radio channel; means for identifying signals having a high probability of correctness of channel signal information; means for identifying signals having a low probability of correctness of channel signal information; means for spreading the signals of the channels having a high probability of correctness of channel signal information; means for subtracting the output of the means for spreading from an output of the means for receiving radio signals to eliminate interference components from received radio signals; and means for recovering signals from the channels having a low probability of correctness of channel signal information;
Claim 2
Dependent Claim 96 words
Apparatus for reception of radio signals in a CDMA spread spectrum radio transmission system as claimed in claim 1, and FURTHER CHARACTERIZED BY the means for identifying signals with a high probability and the means for identifying signals with a low probability both comprise decision logic circuitry for detecting the signals having a high probability of correctness and encoding them with a logic level and for detecting the signals with a low probability of correctness and encoding them with a erasure level, and memory storage for storing the encoded signals having logic levels and erasure levels.
Claim 3
Dependent Claim 49 words
Apparatus for reception of radio signals in a CDMA spread spectrum radio transmission system as claimed in claim 1, and FURTHER CHARACTERIZED BY means for applying signals from the means for recovering signals to the memory and replace the signals with low probablity of correctness with the recovered signals.

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