Receiver for Asynchronous Distributed Transmission over AWGN Channel

Distributed beamforming (DBF) paradigm allows transmission of same signal via multiple transmitters with an aim to achieve coherent reception. The key challenge in DBF is the synchronisation of various transmitters. In this paper, we focus on asynchronous transmission with an aim to detect bits from non-coherent combination of signals at the receiver and present a novel receiver framework for such a distributed asynchronous transmission. We first oversample the received signal and obtain the CFO between the transmitters. Thereafter bits are detected using the generalised likelihood ratio test. We first present the results for a single transmitter single receiver case in the presence of CFO between the two LOs and extend the same to two transmitter and a single receiver case. The performance of the two systems has been evaluated in terms of bit error rate (BER) under AWGN channel. Results show significant improvement in BER as compared with the conventional receiver.