| 摘要 |
<p>A communication device for use in a non-self synchronizing scrambling communication system (400) in which data is transmitted as a series of bits in a digital data stream and a method for using non-self synchronizing scrambling in such a communication system are disclosed. An illustrative device includes means for deriving a set of symbol indices (402) from the series of bits in the digital data stream, means for generating a first pseudo-noise sequence (401) according to a timing reference, the first pseudo-noise sequence having a plurality of elements, each of the elements comprising a constant number of bits that is greater than or equal to the maximum number of bits per symbol at the maximum bit transmission rate of the communication system, and means for combining the symbol indices and the elements of the pseudo-noise sequence (403) to produce a symbol-wise scrambled digital data stream. The scrambled digital data stream may be transmitted over a communication medium and descrambled at the opposing end of the communication medium. Synchronization between the scrambler and the descrambler is maintained by providing a common timing reference to the scrambler and the descrambler. The common timing reference is independent of changes in the data transmission rate. The invention can be used in any digital communication system in which all the communication devices have a common timing reference.</p> |
