Zero-crossing baseband demodulator

In this paper, a new, patent pending, digital baseband demodulator which is cost-effective, low-power, and easy to manufacture, is presented. Unlike conventional baseband digital hardware demodulators which are limited to the demodulation of wideband binary FSK signals in pagers, the proposed baseband demodulator is applicable to both wideband binary FSK and narrowband, multi-level FSK and PSK signals. This demodulator estimates phase rotation angle over one symbol time using the zero-crossings of in-phase and quadrature signals. Also presented is the theoretical performance analysis of the proposed demodulator along with computer simulation results. The performance analysis and computer simulations indicate that the proposed demodulator performs as well as conventional demodulators.