Most of the papers and books dealing with CDMA systems just refer to Gold codes for scrambling processes. It is not fully described why Gold codes are utilized for scrambling.
Can anyone give me a reference about the specification of sequences for scrambling?
Simulation and Software Radios for Mobile Communications By H. Harda.
I will use the GPS as an example. The Gold codes ARE NOT used for scrambling. They are used for correlation acquisition of the C/A code. Robert Gold developed them to have low correlation side lobes in a relatively short digital sequence. He built a career around his discovery and subsequent consulting firm. Low correlation sidelobes minimize false correlation detection. Its been almost 40 years, but if my memory is correct, the GPS Gold codes had side lobes about 20 dB down from the main lobe. CDMA uses long maximal-length sequences, the longer the sequence, and the better the orthogonality, the more uses that can have access to the same RF spectrum. Scrambling of codes for security purposes is usually done with long, non-linear sequences that cannot be easily detected and reproduced. Good luck.
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