Utilizing Sidelobe ASK Based Joint Radar-Communication System Under Fading

Abstract

A joint radar-communication (JRC) system can provide cost-effective and spectrum-efficient platform solution with simultaneous operation, while accomplishing important tasks, sensing via radar processing and allocation of communication links. Existing modulation techniques where information embedding is achieved using sidelobe Amplitude-Shift Keying (ASK) for the JRC system are not investigated so far under fading channels and an optimum threshold estimation algorithm is yet to be developed. Specifying an optimum threshold level under fading can become a comprehensive problem, especially for mobile communication systems. In this paper, a novel non-data aided (NDA) threshold estimation technique and a receiver design are introduced. Furthermore, a new sidelobe ASK modulation technique is proposed for utilizing JRC system for mobile platforms under fading. Proposed modulation technique implements dual Sidelobe Level (SLL) ASK with waveform diversity by exploiting multiple orthogonal waveforms. One pair is modulated with dual SLL in amplitude rotational manner and initiates NDA threshold estimation process at the receiver. This method utilizes $K$ bits of information using only $K+1$. orthogonal waveform. The performance of the proposed technique is investigated in terms of the bit error rate (BER) and data rate. Simulations reveal that the operation of proposed method coupled with NDA threshold estimation process can reach more data rate, since it exhibits almost the same BER performance as existing methods under fading channel without requiring more orthogonal waveform.