Analysis of Optimal Quasi-Orthogonal FH System with Array Receiver for Anti-Interference

In the future, plenty of wireless applications (e.g., Bluetooth, WiFi, Zigbee, and so forth) will be congested in the limited physical resource, which results in the serious interference. In this paper, we exploit a wireless transmission infrastructure to address this issue by occupying the minimum physical resource. Firstly, we introduce an optimal quasiorthogonal frequency-hopping sequence (QO-FHS) set, which has a lower hit-rate but with the less spectral resource than the conventional hopping pattern. Then, a QO-FH based adaptive beam-forming (BF) receiver (QO-FH/BF) is proposed to combat the interference. The theoretical performance of the proposed system in terms of bit-error-rate (BER) is derived as a function of the parameters of QO-FHS set and adaptive BF in the asynchronous access scenario. The numerical and simulation results show that, compared with the conventional FH systems with random hopping pattern, the proposed QO-FH/BF system can remarkably suppress the interference and support the high capacity of network. The anti-interference capability of the proposed QO-FH/BF system depends on the degree of freedom of the combination of QO-FH and BF techniques.