A new mathematical analysis of the cyclic prefix effect on removing ISI and ICI in DMT systems

Abstract

In this paper, a new mathematical analysis is presented that shows the effects of cyclic prefix insertion on removing inter symbol interference (ISI) and inter carrier interference (ICI) in the discrete multi-tone (DMT) systems. In the DMT, for subcarriers modulating, the input data stream is divided into lower rate sub-streams. The ISI is eliminated almost entirely by adding a guard interval (GI) at the beginning of each DMT symbol. However, rather than using an empty GI, this interval is filled with the end part of the DMT symbol. Through this method ISI and ICI are avoided. In all the previous works, the authors have shown the above results by only matrix analysis, without any information insight in different steps, but in this work we analyze it by a new method via signal processing analysis for the first time. Therefore, one knows what will be happen for every symbol in each step.

Analysis of cyclic prefix length effect on ISI limitation in OFDM system over a Rayleigh-fading multipath

“…After Parallel to serial conversion, we can finally obtain the OFDM symbol [9]. At the receiver, the inverse operations are performed; starting with the removal of the cyclic prefix [10], the spectral decomposition of the received samples calculated using the FFT algorithm [15] and finally the demodulation [16], in the case of performing a channel estimation and additional stage is added to estimate the response of the transmission channel [17]. of the products on their common (fundamental) period is zero.…”

“…In the following section we present the expression of SINR as a function of the following parameters: symbol length [8], CP length [18], multipath and the thermal noise [16]. The CP length is Δ seconds.…”

An efficient OFDM-based system with an insufficient cyclic prefix via a novel constellation algorithm

“…The second term represents the intercarrier interference (ICI) caused by other subcarriers belonging to the current OFDM symbol. Finally, the third term represents the ISI caused by the subcarriers of the previous OFDM symbol [23].…”

“…The GI part of each symbol is filled with copying the end part of the same symbol. In [23] it is shown that after removing GI in the receiver, the final r k ′ ,m ′ term will be…”