| 摘要 |
A communication system ( 20 ) uses TDMA techniques to distinguish intended recipients of a communication signal ( 26 ) from one another, and direct sequence spread spectrum (DSSS) techniques to encode and distinguish diverse parallel substreams ( 70, 74 ) of each user's data stream. Parallel unspread substreams ( 70 ) are spread using cyclic variations of a common spreading code ( 38 ). In one embodiment, the common spreading code ( 38 ) is chosen for low aperiodic autocorrelation sidelobes and a substantially flat spectral analysis. In another embodiment the common spreading code ( 38 ) is chosen for low periodic autocorrelation sidelobes and a substantially flat spectral analysis. In one embodiment, the use of cyclic variations of the spreading code ( 38 ) along with a cyclic prefix ( 114 ) enables the mathematical communicative matrix multiplication property, thereby permitting equalization for multipath to occur following or in conjunction with despreading.
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