Digital block phase and frequency offset estimation in burst mode MSK transmission

Acquisition of burst mode packetised data over a satellite channel involves frequency offset estimation and block phase estimation for coherent demodulation of data. The paper describes a non-decision directed, asynchronous block phase estimator for use in demodulation of baseband MSK in-phase and quadrature (I&Q) signals for AWGN channels. Automatic frequency compensation (at intermediate frequency) through a control voltage to a VCXO is provided using LMS parameter estimation on the carrier recovery bits present in the preamble of every burst. The MSK-burst modems have been implemented in real time at 16 kbps using a TMS320C30 based DSP board