Frequency offset compensator for land mobile zero-crossing digital FM receiver

A base-band demodulator called zero-intermediate frequency zero-crossing demodulator (ZIFZCD) was developed. The ZIFZCD is mostly implemented in digital hardware which offers low power consumption, small size and ease of manufacture. The frequency offset effect on the performance of the ZIFZCD has been studied and a significant bit error rate (BER) degradation has been observed. Two frequency offset compensation schemes are presented to overcome the BER degradation problem and to improve the BER performance of the ZIFZCD. One is called the "DC frequency offset compensator" and the other one is called the "click compensator" which is developed by reducing the effect of click noise. These frequency offset compensation schemes can be applied to a nonzero-intermediate frequency zero-crossing demodulator (NZIFZCD). A significant BER improvement can be obtained by the frequency offset compensator or click compensator.