Spread-Spectrum Despreading Without the Code

A new method for despreading direct-sequence spreadspectrum signals, without use of the spreading code, is evaluated by analysis and simulation. The new method exploits the cyclic autocorrelation in place of the conventional autocorrelation, which was used in a prior method. Both methods require that the period of the code be equal to a multiple of the data symbol interval. Broad-band noise and narrowband interference rejection capabilities of both methods are compared. It is shown that the new method, unlike the prior method, can provide substantial immunity to strong narrow-band interference.