Synchronization techniques for multicarrier QPSK demodulators

Considers the synchronization algorithms which are suitable for a QPSK multichannel demodulator. The solid structure of the demultiplexer forbids any feedback of signals to the analog part. As a result the algorithms employed must operate on asynchronously sampled signal with uncontrolled amplitude gain. In addition, algorithmic simplicity and near optimum performance is desirable. The authors have selected and modified for this application the most recent algorithms because of their superiority in performance and their simplicity. A complete differentially encoded QPSK demodulator structure is given and its transient and steady-state performances have been evaluated by computer simulation