Quadratic multiplexing--A new method for secure communication (Corresp.)

A secure discrete-time multiplexing technique is presented which uses a pseudorandom process with a fundamental cycle length . The method can handle signal sequences of length . If all the signals have the same bandwidth, the multiplexed signal will have that bandwidth. When is large the signal-to-noise ratios of the demultiplexed signals are high, even if the additive noise power is large. The demultiplexer most compute the same pseudorandom sequence that is used to encode the signals. Demultiplexing requires 3 multiplications and additions.