SearcharxivSearch

arXiv subjects

Fernando Cruz-Roldán

Publications and source records attributed to Fernando Cruz-Roldán.

3 recordsLinked to original sources

Intersymbol and Intercarrier Interference in OFDM Systems: Unified Formulation and Analysis

A new unified formulation for seven different orthogonal frequency-division multiplexing (OFDM) systems is presented. The proposed formulation relies on six parameters and encompasses conventional OFDM systems, with windowing in the transmitter and/or in the receiver, and also with a cyclic prefix (CP) or both a CP and cyclic suffix (CS). A new equivalent channel matrix that is useful for calculating both the received signal and the intersymbol and intercarrier interference power is defined and characterized. Unlike previous works, this new channel matrix formulates the channel convolution with no restrictions on the length of the channel impulse response. Moreover, it includes the overlap-and-add procedure performed in the transmitter of windowed OFDM systems. Furthermore, new theoretical expressions for the intersymbol and intercarrier interference and also for the signal-to-interference-plus-noise ratio are derived.

eess.SP

Intersymbol and Intercarrier Interference in OFDM Transmissions through Highly Dispersive Channels

This work quantifies, for the first time, intersymbol and intercarrier interferences induced by very dispersive channels in OFDM systems. The resulting achievable data rate for \wam{suboptimal} OFDM transmissions is derived based on the computation of signal-to-interference-plus-noise ratio for arbitrary length finite duration channel impulse responses. Simulation results point to significant differences between data rates obtained via conventional formulations, for which interferences are supposed to be limited to two or three blocks, versus the data rates considering the actual channel dispersion.

eess.SP

Throughput Analysis for Wavelet OFDM in Broadband Power Line Communications

Windowed orthogonal frequency-division multiplexing (OFDM) and wavelet OFDM have been proposed as medium access techniques for broadband communications over the power line network by the standard IEEE 1901. Windowed OFDM has been extensively researched and employed in different fields of communication, while wavelet OFDM, which has been recently recommended for the first time in a standard, has received less attention. This work is aimed to show that wavelet OFDM, which basically is an Extended Lapped Transform-based multicarrier modulation (ELT-MCM), is a viable and attractive alternative for data transmission in hostile scenarios, such as in-home PLC. To this end, we obtain theoretical expressions for ELT-MCM of: 1) the useful signal power, 2) the inter-symbol interference (ISI) power, 3) the inter-carrier interference (ICI) power, and 4) the noise power at the receiver side. The system capacity and the achievable throughput are derived from these. This study includes several computer simulations that show that ELT-MCM is an efficient alternative to improve data rates in PLC networks.

cs.IT