FDMA System with Space–Time Encoded CPM Signals

Abstract

The paper considers a multiple-antenna uplink wireless transmission (MIMO) system in a Frequency Division Multiple Access multi-user environment. It involves a concatenation of Space-Time Block or Trellis Codes (STBC or STTC) with Continuous Phase Modulation (CPM). For a more efficient available band utilization, the distances between individual system user carriers are small (tight intercarrier frequency spacing). Such a solution causes the deterioration of transmission quality due to the occurrence of Inter-Channel Interference (ICI). In order to reduce the bit error rate (BER), a combination of CPM and STTC has been used, along with a Minimum Mean Square Error (MMSE) MIMO detector and a low-complexity iterative algorithm for Inter-Carrier Interference (ICI) cancellation on the receiver side. BER results obtained in computer simulations are presented for the proposed system.