Efficient Amplitude Shift Keying-Aided Orthogonal Chaotic Vector Position Shift Keying Scheme With QoS Considerations

In this paper, we present an efficient amplitude shift keying (ASK)-aided orthogonal chaotic vector PSK (ASK-OCVPSK) non-coherent modulation scheme with considerations of different quality of service (QoS) demands. In our ASK-OCVPSK design, the reference chaotic signal is generated recursively from the shifted chaotic vectors orthogonalized by the Gram-Schmidt transform buffered in the shift register. Then, we embed the information on both the position and the amplitude of the chaotic sequence. The binary information bitstream is divided into two segments, which are modulated, respectively, by the parallel concatenated position shift keying (PSK) scheme and the ASK scheme. Next, the ASK symbol is further modulated by the PSK modulated chaotic vector, and the resultant symbol is transmitted together with the reference chaotic vector. Notably, with the aid of the shift register, only one chaotic vector is transmitted and the reference chaotic sequences can be easily regenerated recursively at the receiver for information recovery. Furthermore, we derive the theoretical bit error rate (BER) expressions for the proposed system over additive white Gaussian noise (AWGN) channel. Then, the spectrum efficiency and the complexity of the proposed scheme are analyzed and compared with those of the counterpart schemes. Simulations are performed over the AWGN channel and multipath Rayleigh fading channel, and the results demonstrate that the theoretical BER matches the simulation results. Moreover, the results verify that the presented scheme are more efficient and more reliable than the counterpart schemes and can provide different BER performances without changing the modulator structure to meet the different QoS demands of the users.