Reference parameter estimation in the presence of a frequency shift in burst mode PSK transmission

In burst transmission rapid carrier and clock recovery is a key aspect. When a preamble is used to recover the reference parameters it is important to have a feedforward structure which allows these parameters to be estimated quickly, simultaneously and directly. The feedforward structure is generally very sensitive to frequency offsets, leading to a systematic bias and to an increase in the mean reference parameter square estimation error. In this paper the authors propose a dedicated algorithm for clock and carrier synchronization in a PSK demodulator operating in single channel per carrier (SCPC) mode, which performs efficient estimation even in the presence of a not negligible frequency offset. The algorithm is based on use of a very short special carrier preamble modulated by a known pattern and is very easy to implement with digital hardware.