| 摘要 |
Using CDMA encoding and spectrum spreading with a factor N, more than N messages are transmitted although N is a theoretical limit for this type of encoding. Encoding uses orthogonal sequences for a first group of N messages and random or pseudo-random sequences PN for a second group of M-N additional messages. On reception, the N messages of the first group are decoded and detected. Their interference is subtracted from the second group of M-N messages before detecting the M-N messages. In a second iteration, the interference of the M-N messages using PN sequences is estimated and subtracted from the N first messages before a second detection on the first group of N messages. Detection is then repeated for the second group of M-N messages after subtracting the interference of the first group of N messages and the mutual interference of the M-N messages.
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