A novel M-FSK receiver using an acoustooptic deflector

A novel receiver for M-FSK signals using an acoustooptic deflector (AOD) is presented. The error performance of this receiver in the presence of AWGN is the same as that of a coherent M-FSK receiver. The tone spacing in the proposed receiver is the same as in a noncoherent receiver. The presented receiver saves the hardware complexity encountered in conventional M-FSK coherent or noncoherent receivers, especially for large M. The AO M-FSK receiver also provides less interference from neighboring symbols, which results in improved error performance. It has ideal bandpass filters and the pulse shape can be changed which minimizes interference. Commercially available AODs can demultiplex M-FSK signals with several tens of GHz bandwidth and with M as large as one thousand. The geometry, design, and operation of ail AO M-FSK receiver is introduced, error performance is discussed, and interference analysis is presented. Computer simulation for an AO M-FSK receiver with M=128 is presented and results are shown.