Pulse or digital communications – Repeaters – Testing
Patent
1991-08-02
1993-06-08
Cain, David
Pulse or digital communications
Repeaters
Testing
H04K 100
Patent
active
052186199
ABSTRACT:
Subtractive CDMA demodulation optimally decodes a coded information signal embedded in many other overlapping signals making up a received, composite signal. A radio receiver correlates a unique code corresponding to the desired signal to be decoded with the composite signal. Moreover, after each information signal is successfully decoded, it is recoded and removed from the composite signal. Subtractive CDMA demodulation is enhanced by decoding the composite signal in the order of strongest to weakest signal strength. The individual information signals are spread using block error correction codes which are correlated with the composite signal using Fast Walsh transforms. Correlated signals identified as the largest transform component are removed from the composite signal and the remaining composite signal is reformulated using an inverted Fast Walsh transform. Any residual error or interference caused during the extraction of a transform component is removed by recorrelating the composite signal using the index of that transform component.
REFERENCES:
patent: 4644560 (1987-02-01), Torre et al.
patent: 4901307 (1990-02-01), Gilhousen et al.
patent: 4930140 (1990-05-01), Cripps et al.
patent: 4984247 (1991-01-01), Kaufmann et al.
patent: 5022049 (1991-06-01), Abrahamson et al.
"Very Low Rate Convolutional Codes for Maximum Teoretical Performance of Spread-Spectrum Multiple-Access Channels", Andrew J. Viterbi, IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, May 1990, pp. 641-649.
Cain David
Ericsson GE Mobile Communications Holding Inc.
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