Patent ID: 7155016

Claim:
A communication device for scrambling a digital data stream for use in a non-self-synchronizing scrambling (NS3) communication system, said system supporting a variable number of bits per symbol less than or equal to a maximum number of bits per symbol, said digital data stream comprising a series of bits and having a bit transmission rate, the communication device comprising: means for converting each N bits of the digital data stream into a symbol index to produce a stream of symbol indices; means for generating, at a rate derived from a symbol rate and different than the bit transmission rate, a pseudo-noise sequence (PNS), said PNS comprising M output bits, wherein M is at least as large as said maximum number of bits per symbol and M is independent of N; and means for modifying said stream of symbol indices based on said PNS to produce a symbol-wise scrambled digital data stream, wherein said symbol-wise scrambled digital data stream is capable of being descrambled by a second modifying means that is the inverse of said modifying means.