Modulation diversity for differential amplitude and phase shift keying technique

M Kanthimathi,S Anusha,R Amutha

doi:10.14419/ijet.v7i1.1.9946

Abstract

Modulation diversity can reduce the bit error rate in fading channels. We make use of the advantage of modulation diversity in non-coherent differential modulation technique. Increase in modulation diversity is obtained by rotating signal constellation. Coordinate interleaved Differential amplitude and phase-shift keying modulation (DAPSK) is particularly advantageous compared to the Differential phase-shift keying (DPSK) technique. Energy optimization is done to minimize the energy consumption. Simulation results shows that the proposed differential detection for different rotation angle achieves better BER performance than constant phase differential detection with modulation diversity.The energy required to successfully transmit a bit is also reduced for proposed system compared to Differential phase shift keying based system.

Highlights

Signal space diversity combined with differential detection is very effective in scenario where actual channel state information is difficult to achieve
It eliminates the pilot symbols for estimating the channel information and equalization. Efficient technique such as Differential amplitude and phase-shift keying modulation (DAPSK) is advantageous compared to Quadrature amplitude modulation (QAM) in distortion environment where signal compression take place and this is explained in [1]
We derive optimization based on the signal constellation parameters to minimize the required energy and analyze the energy consumption per bit for the differential detection technique

Summary

Introduction

Signal space diversity combined with differential detection is very effective in scenario where actual channel state information is difficult to achieve. It eliminates the pilot symbols for estimating the channel information and equalization. In this work we combine the benefits of signal space diversity in DAPSK modulation scheme in block fading channel. We derive optimization based on the signal constellation parameters to minimize the required energy and analyze the energy consumption per bit for the differential detection technique.

DAPSK energy consumption

Simulated results

Conclusion