Comparison of Passband and Baseband Transmission Schemes for Power-Line Communication OFDM Systems

Passband and baseband transmissions are two competing transmission schemes for power-line communication (PLC) orthogonal frequency-division multiplexing (OFDM) systems. The advantage of the former is that it is simpler to implement for digital circuits as it needs the half-size inverse fast Fourier transform/fast Fourier transform. As will be shown, there are synchronization errors, such as carrier frequency offset (CFO) and sampling frequency offset (SFO) that degrade the performance of passband transmission. On the other hand, baseband transmission is expected to be less complex in an analog circuit implementation and to be affected by only SFO, since it does not need up-down conversion. Both CFO and SFO are caused by the frequency errors of the reference clocks in the transmitter and receiver. In this paper, signal-to-interference-plus-noise ratios and capacities are considered in comparing the effects of synchronization errors in passband and baseband transmissions. The results indicate that the performance degradation of passband transmission is almost the same as that of baseband transmission in the presence of synchronization errors.