Pilot-Based Compensation Scheme for Signal Distortion with Hexagonal Constellation

Quadrature Amplitude Modulation (QAM) is a multi-level modulation scheme applied to achieve high data transmission rates. In the 16-QAM scheme, high Peak-to-Average Ratio (PAPR) is an issue as wireless communication devices are required to be small with high power efficiency. To resolve this issue, hexagonal constellation symbol mapping has been proposed to reduce the PAPR. In a real environment, Orthogonal Frequency Division Multiplexing (OFDM) systems are sensitive to signal distortions such as multipath channel and frequency offsets. When the pilot signals are used to compensate the signal distortion, the combination of pilot signals and mapping need to be considered. The paper investigates the PAPR of the hexagonal constellations and examines the relationship between the PAPR and the interval of pilot signal in OFDM system. Bit Error Rate (BER) performance are evaluated with computer simulations.