Finding Good Signalling Codes with Custom VLSI

Digital communications on a shared, random access channel benefits from good codes to synchronize and to multiplex the data. Such codes have high autocorrelation and low crosscorrelation, respectively. Finding long binary sequences with these properties is difficult, and generally involves significant brute force searching. A custom computing engine performs such a search much faster than other approaches, and a custom VLSI chip is a practical means of constructing such an engine. The practical advantages and costs of this approach are discussed.