Proportionally Sampled Multicarrier Modulation

A new proportionally sampled multicarrier modulation (PSMCM) system with optimum receiver is presented in this paper. By adopting different sampling rates at transmitter and receiver, the PSMCM system can achieve multipath diversity with simple linear operations. It has the same spectral efficiency as conventional orthogonal frequency division multiplexing (OFDM) system, while doesn´t require complex precoder/decoder as used by most other multicarrier systems for the fulfillment of multipath diversity. In addition, it is insensitive to timing phase offset caused by the phase difference between transmitter clock and receiver clock, thus eliminates the need of precise sample level synchronization as required by conventional OFDM system. Exact bit error rate expression of the new system is derived. Both analytical and simulation results show that PSMCM system outperforms OFDM system with the same spectral efficiency by as much as 10 dB.