Bit Error Rate Performance of OFDM Using Hierarchical Modulation in 3GPP TDL Channel Model

This paper presents the average bit error rate (BER) performance of orthogonal frequency division multiplexing using two-layer and three-layer hierarchical modulation (HM) schemes in a multipath Rayleigh fading channel based on a 3GPP tapped delay line channel model. In HM, the basic information bits should be demodulated and decoded using all the users within a cell satisfying the BER requirement. Hence, we investigate non-uniform quadrature amplitude modulation constellations so that the loss in the required average received signal-to-noise power ratio (SNR) satisfying the average BER of the basic information bits for HM is minimized compared to that using the original constellation with which only the basic information bits are transmitted. We also investigate the distance from a cell site in the coverage area for the information bits of each layer based on the path loss equations in the Urban Macro and Rural Macro scenarios in terms of the required average received SNR achieving the average BER of 10 ⁻³ .