Statistical characteristics of MIMO-OFDM transmission systems in a multipath environment where the delay spreading exceeds the guard interval

Abstract

SUMMARYOrthogonal frequency division multiplex (OFDM) modulation systems can completely prevent intersymbol interference due to multipath propagation by providing a guard interval which is longer than the maximum delay hereafter we call "delay spreading." In an environment in which the delay spreading exceeds the guard interval, on the other hand, intersymbol interference occurs. This study considers a MIMO-OFDM system in which a MIMO configuration with high diversity gain is introduced into the OFDM modulation scheme, and discusses the transmission characteristics of maximal ratio combining transmission (single-stream transmission). It is shown that the MIMO-OFDM system is less affected by intersymbol interference due to the delay, even if the delay spread exceeds the guard interval, and that good performance is achieved. It is also shown that the channel response which is required in realtime control can be estimated with sufficient accuracy.

Innovative Antennas and Propagation Studies for MIMO Systems

“…The floor value of BER for MIMO with OFDM/DQPSK after MRC is shown in Fig. 13 [20]. As is evident from the figure, when the ratio T GI /σ τ is increased, the BER is decreased drastically, indicating that the condition given in Eq.…”

“…Figure 12(a)-(d) is examples of the received power characteristics (Power: solid lines) and the error distribution statistics (BER: bar graph) for the link connecting each transmitting antenna and each receiving antenna (corresponding to four single-input singleoutput (SISO) cases) in 2 × 2 MIMO, in fading where the delay profile exceeds the guard interval [20]. Since the thermal noise is not included in the simulation, the generated errors are due to ISI and ICI.…”

Statistical Multipath Propagation Modeling for Broadband Wireless Systems

“…The MIMO diversity function is also studied as a method of simultaneously suppressing errors due to thermal noise and inter-symbol interference [59]. These research trends are not within the scope of the survey of propagation models and so are not detailed here.…”