Conventional OFDM systems employ a guard interval to combat delay spread di
stortion of transmitted data. This reduces the efficiency of the OFDM trans
mission. A combined OFDM-Equalization reception strategy is presented in th
is paper. This strategy employs an Adaptive Equalizer to combat delay sprea
d distortion instead of a guard interval. This facilitates the use of very
short guard intervals and thus the transmission efficiency of the OFDM modu
lation scheme is improved. This paper presents the combined OFDM-equalizati
on receiver and the pre-FFT equalizer designs. The efficiency of both the c
onventional OFDM and combined OFDM-equalization strategies is considered an
d it is demonstrated that combined OFDM-equalization offers a significant i
mprovement in transmission efficiency. The transmission of OFDM signals in
Single Frequency Networks is considered and it is shown that the combined O
FDM-Equalization technique is particularly effective for such applications,
offering an improvement in bandwidth efficiency of 14% under severe delay
spread conditions. The limitations of the combined OFDM-equalization strate
gy to operate effectively under both additive noise and time variant condit
ions are considered. Performance is simulated and the sensitivity to this i
mpairment analyzed.