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