Performance Assessment of OFDM-Based Wireless Networks

Abstract

The fundamental modulation scheme of 4G LTE and 5G networks is Orthogonal Frequency Division Multiplexing (OFDM), which, however, has a high Peak-to-Average Power Ratio (PAPR). This elevated PAPR greatly impairs the efficiency of the High-Power Amplifier (HPA) and consumes mobile battery power. The present paper provides a comparative study of three PAPR reduction methods: Amplitude Clipping, Selective Mapping (SLM) and Partial Transmit Sequence (PTS) based on a 64-QAM constellation using the Simulink. Our results indicate that although Amplitude Clipping is a successful tool to reduce the PAPR, it compromises the Bit Error Rate (BER) irreparably with non-linear distortion. On the other hand, SLM maintains signal integrity but imposes huge computational complexity, posing a threat to 5G ultra-low latency. As a result, PTS can be considered the best possible solution. PTS greatly reduces the range of powers by dividing data into sub-blocks and dynamically leveraging phase factors. Extensive waveform and BER measurements confirm that PTS is able to stabilize peak levels and remain able to maintain the uncompromising data reliability, which is necessary to enable the next generation wireless infrastructure with proper power-linearity.