Bit Synchronization of PCM/FM Signals at Low SNR

In this study, a novel bit synchronization method for the telemetry digital Intermediate Frequency (IF) receiver of PCM/FM signals at low Signal-Noise Ratios (SNR) is proposed. Bit synchronization is also known as symbol synchronization, which is an important technique in the communication systems nowadays and it is essential in both baseband transmission and radio-frequency transmission systems. An imperfect bit synchronization algorithm will affect the performance of the communication system and even cause the communication system work abnormally. As SNR in PCM/FM telemetry system is much lower than other conventional communication systems, traditional bit synchronization algorithms can't meet the requirements. So by means of the mean filtering technique in image processing, a novel bit synchronization algorithm at low SNR for PCM/FM based on FPGA is proposed and has already been implemented in our telemetry digital IF receiver. Via simulations, it is shown that this algorithm can achieve excellent performance at low SNR. © 2010 Asian Network for Scientific Information.