MSK Receiver with Low Complexity and Multi-symbol Joint Detection

Abstract

Cooperative engagement capability of unmanned aerial vehicle (UAV) will be the key to the future warfare. The prerequisite is a stable and reliable UAV communication data link. Minimum shift keying (MSK) modulation has good bandwidth and power efficiency. Meanwhile, it has good anti-phase noise deterioration capability. Therefore, MSK modulation is quite suitable for UAV communication data link. However, the traditional MSK receiver either has a large difference between receiving performance and the theoretical value, or has high complexity, which means it is not applicable. Based on the maximum likelihood criterion, this paper introduces an MSK receiver structure for UAV data link. We made use of the phase continuity among MSK modulation symbols and bring in a low-complexity non-coherent block detection module which is called NBD module. We simplified the receiver structure while ensuring the receiving performance. The simulations show that, with the condition of AWGN channel and bit error rate (BER) of 10$^{-5}$, the demodulation threshold of NBD algorithm with 5-channel differentials is 2.6 dB lower than that of one-bit differential algorithm and 3.3dB lower than that of the non-coherent envelope detection.