Digital ultrafast carrier recovery for interactive transmission systems

An ultrafast, all-digital method for phase synchronization and coherent carrier recovery is presented for time division multiple access (TDMA) and code division multiple access (CDMA) burst data communication systems. A new adaptive phase tracking (APT) method, presented and analyzed in this paper, uses a hard-limited IF signal in a feed forward configuration for carrier phase detection and recovery. A novel new technique of phase window filtering is presented as a means to combat noise induced phase errors, and improved the performance of a digital controlled phase shift oscillator by 7 dB. Experimental measurements show APT provides robust bit error rate (BER) performance within 1 dB of the theoretical binary phase shift keyed (BPSK) and tenths of dBs of an ideal hard wired clock. APT achieves acquisition within one- to four-bits-5 to 10 times faster than present requirements. A low power, low cost single chip fast carrier synchronization and demodulation solution for QPSK, GMSK and GSM compatible OQPSK and Feher's quadrature phase shift keyed (FQPSK) and binary phase shift keyed (FBPSK) systems are also presented.