Abstract :
We study uncoded bit-error-rate (BER) performances of single-carrier block transmissions, zero-padded (ZP), and cyclic-prefixed (CP) transmission, when linear equalizers are applied and the BERs are averaged over one block. We show analytically that the BER of ZP transmission with linear equalization degrades as the bandwidth efficiency increases, i.e., there is a tradeoff between BER and bandwidth efficiency in ZP transmission. It is also proven that when minimum mean-squared-error (MMSE) equalization is adopted, ZP transmission outperforms CP transmission and uncoded orthogonal frequency-division multiplexing (OFDM) on the average over random channels. However, the difference between the ZP and the CP transmission becomes smaller as the block size gets larger, since the average BER performance of the ZP transmission degrades, while the average BER performance of CP transmission improves, as a function of the block size. Numerical examples are provided to validate our theoretical findings and to compare the block transmission systems
Keywords :
OFDM modulation; equalisers; error statistics; fading channels; mean square error methods; multipath channels; bandwidth efficiency; cyclic-prefixed transmission; linear equalization; minimum mean-squared-error equalization; multipath fading channels; random channels; single-carrier block transmissions; uncoded bit-error-rate performance; uncoded orthogonal frequency-division multiplexing; zero-padded transmission; Bandwidth; Bit error rate; Degradation; Fading; Fast Fourier transforms; Frequency division multiplexing; Intersymbol interference; Multipath channels; OFDM; Transmitters; Block transmission; linear equalization; multipath channel; orthogonal frequency-division multiplexing (OFDM);
