Problems of Synchronization and Non-Linear Distortion and Their Effect on the Detection of Walsh Functions

Walsh functions are potentially applicable to random-access communication provided that requirements for system synchronization and channel linearity are not too severe. This paper investigates the problem of detection of a desired Walsh-code modulated sinusoidal carrier in the presence of other signals for the case when synchronization is not achieved among the users of the system. It is shown that by proper selection of Walsh codes, the synchronization requirements can be alleviated considerably and it may be possible to operate the system asynchronously. The effect of hardlimiting and the problem of transmitting a number of Walsh signals through a power-law device are also considered.