New baseband zero-crossing demodulator for wireless communications. II. Performance under fading channel

In Part I (see MILCOM 95, San Diego, vol.2, p.543, 1995) a new efficient baseband receiver for the wireless communication systems was introduced. This receiver, known as "zero-intermediate frequency zero-crossing demodulator (ZIFZCD)", is much simpler than conventional receiver and easily implemented using digital hardware integrated circuits. In Part I the performance of the ZIFZCD under static environments was compared with that of the limiter-discriminator-integrate and dump filter (LDI). In this paper, the performance of the ZIFZCD under mobile fading environments is presented. Also presented is the investigation of the effects of frequency offsets, and phase and gain imbalance on performance. For a narrowband continuous phase frequency shift keying (CPFSK) signal with the modulation index, h, equal to 0.5, the ZIFZCD is found to perform in fading environment comparably with the LDI. For a CPFSK with h greater than 1, the ZIFZCD is found to perform significantly better than the LDI.