In this letter, we propose a simple adaptive switching scheme to enhance the performance of space-time/frequency block coded OFDM systems (STBC/SFBC-OFDM). Since STBC-OFDM and SFBCOFDM undergo severe performance degradation in timeand frequencyselective fading channels, respectively, performance enhancement can be achieved by switching between STBC-OFDM and SFBC-OFDM over a continuously varying...

The 60 GHz band is of much interest since this is the band in which a massive amount of spectral space (5 GHz) has been allocated unlicensed worldwide for dense wireless local communications. Orthogonal frequency division multiplexing (OFDM) has gained much popularity in the field of wireless communication because of its ability to transfer the data at higher rate, high bandwidth efficiency and...

This paper investigates the Multi-band OFDM (MB-OFDM) based physical (PHY) layer proposal for IEEE 802.15.3a working group on short-range high data-rate Ultra-wideband (UWB) communications. An overview of the MB-OFDM PHY layer architecture with its various parameters is presented and the optimal choice of critical parameters is discussed. Performance results on IEEE UWB channel models are analy...

This article deals with channel estimation (CE) in orthogonal frequency division multiplexing (OFDM)/OQAM. After a brief presentation of the OFDM/OQAM modulation scheme, we present the CE problem in OFDM/OQAM. Indeed, OFDM/OQAM only provides real orthogonality therefore the CE technique used in cyclic prefix-OFDM cannot be applied in OFDM/OQAM context. However, some techniques based on imaginar...

The increasing demand on real time application to achieve high throughput, reliable wireless system and network capacity for fourth generation wireless local area networks is to combine MIMO wireless technology with OFDM. Orthogonal Frequency Division Multiplexing (OFDM), which offers reliable high bit rate wireless system with reasonable low complexity. OFDM does provide large data rates with ...

End-to-end learning systems are conceived for Orthogonal Frequency Division Multiplexing (OFDM)-aided optical Intensity Modulation paired with Direct Detection (IM/DD) communications relying on the Autoencoder (AE) architecture in deep learning. We first propose an AE-aided Layered ACO-OFDM (LACO-OFDM) scheme, termed as LACONet, exploiting increased bandwidth efficiency of LACO-OFDM. LACONet em...

We propose and experimentally demonstrate a new scheme to reduce the energy consumption of optical network units (ONUs) in orthogonal frequency division multiplexing passive optical networks (OFDM PONs) by using time-domain interleaved OFDM (TI-OFDM) technique. In a conventional OFDM PON, each ONU has to process the complete downstream broadcast OFDM signal with a high sampling rate and a large...

Orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (TDM) bridges the conventional OFDM and single carrier (SC) transmission. For a coded OFDM/TDM system with frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion in a frequency-selective fading channel, there is a trade-off between coding gain and frequency diversity effec...

-Multi-carrier modulation has been used in many wired and wireless communications. It was used in many military high frequency radios, audio-video broad casting and DSL. Multi-carrier modulation can be digitally implemented using Orthogonal Frequency Division Multiplexing (OFDM).Inter symbol Interference can be completely avoided in OFDM by inserting cyclic prefixes. In OFDM wide band channel b...

Orthogonal frequency division multiplexing (OFDM) is a parallel transmission method, where single data stream is separated into a number of lower rate subcarriers, and each carrier is orthogonal to all other carriers. One of the main problems for OFDM system is Carrier frequency offset (CFO). OFDM is sensitive to CFO, which spoils the orthogonality between the sub-carriers, and cause Inter-carr...