The Performance Analysis of Non-coherent M-ary DPSK Receiver Applying the Repetition Scheme for Low-power Communications

Abstract

In this paper, we analyze performance of a non-coherent M-ary differential phase shift keying (DPSK) receiver applying the repetition scheme for low-power and reliable communications. The well-known feature of a non-coherent DPSK is that significantly low complexity implementation can be achieved over coherent PSK, since there is no need of phase synchronization of the received signal, while the receiver performance becomes worse. In order to achieve robust detection performance, a repetition code with error-correction capability can be jointly employed with DPSK. For example, M-ary DPSK modulation with bit spreader and interleaver is used in IEEE 802.15.6 WBAN and IEEE P1901.2 for reliability improvement. In this paper, on the other hand, we employ the symbol repetition instead of bit repetition in order to find possibility of additional performance gain. To be specific, the error rate of a noncoherent M-ary DPSK receiver with repetition scheme is influenced by the noise distribution shape whose effect changes in accordance with a repetition order. In other words, we confirmed that when certain repetition order in each modulation order is given, a noise distribution forces a received signal to be distributed more within or outside error decision boundary. That is, our proposed scheme can be helpful in reducing the bit error rate for non-coherent M-ary DPSK with repetition. In addition to simply employing symbol repetition, an alternative that can achieve higher reliability via exploiting further information at signal demodulation is proposed. In this paper, we investigate performance of a non-coherent M-ary DPSK receiver with symbol repetition by performing the simulation and experiments. In addition, we find the repetition order which can optimize the energy efficiency of a non-coherent M-ary DPSK receiver. ⓒ 2016 DGIST