In this paper, we describe the Orthogonal frequency division multiplexing (OFDM) is an established technique for wireless communication applications. Typical constraints faced during OFDM transmission are: a large peak-to-mean envelope power ratio, which can result in significant distortion when transmitted through a nonlinear device, such as a transmitter power

In this letter, we propose a combined scheme of minimum mean square error (MMSE) detection and successive interference cancellation (SIC) for multiuser space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems. With the same complexity order, the proposed scheme provides significant bit error rate (BER) performance improvement over the linear MMSE multiuser detector....

Space-time block codes provide substantial diversity advantages for multiple transmit antenna systems at a low decoding complexity. In this study, we concatenate both space-time block and trellis codes with Turbo Convolutional (TC) coded Orthogonal Frequency Division Multiplexing (OFDM) for achieving a high coding gain. The associated performance and complexity of the coded OFDM schemes is comp...

We proposed a novel rate-1, space-frequency (SF) code for an Orthogonal Frequencey Division Multiplexing (OFDM) system with transmit (M ) and receive (N ) antennas that achieves the maximum diversity attainable over frequencyselective channels. Since the SF code symbol is transmitted in one OFDM block duration, it has smaller processing delay than previously proposed Space-Time-Frequency (STF) ...

Orthogonal frequency division multiplexing (OFDM) is regarded widely as the key underlying air interface technology for wireless systems such as WiMAX, 3GPP long-term evolution (LTE), and 3GPP2 ultra-mobile broadband (UMB). Due to the inherent nature of these technologies, OFDM signals have high peak-to-average power ratio (PAR) that adversely affects the efficiency of power amplifiers (PAs) us...

In this paper, we describe a approach for reducing the power consumption and complexity of a multiband orthogonal frequency division multiplexing (MB-OFDM) for ultra wideband (UWB) system by applying ideas from pulsed UWB systems. The approach is quite general and applicable to many other systems. Unlike the MB-OFDM system, the enhancement that we propose uses pulses with duty cycles of less th...

In this contribution, we investigate the effect of carrier phase errors on the performance of orthogonal frequency division multiplexing (OFDM) and multicarrier code-division multiple access (MC-CDMA). We show that OFDM and MC-CDMA have essentially the same sensitivities to carrier phase errors. A constant carrier phase offset yields no degradation of the system performance. We show that OFDM a...

The inphase/quadrature (I/Q) amplitude and phase imbalance effects are studied in coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. An analytical model for the I/Q imbalance is developed and supported by simulation results. The results indicate that the I/Q imbalance degrades the BER performance considerably. Keywords—Coherent detection, I/Q imbalance, OFDM, optical...

This article establishes a performance comparison between the OFDM (Orthogonal Frequency Division Multiplexing) and the SCCP (Single Carrier with Cyclic Prefix) systems from the interleaver point of view. Some interleavers schemes are analyzed in a block fading channel scenario, as well as in the context of deep fade static channels. Keywords— OFDM, SCCP, interleaving, frequency selective chann...

A promising solution for significant increase of the bandwidth efficiency and transmission capacity is the exploitation of the spatial dimension, by using Space Division Multiplexing (SDM). SDM algorithms exploit the richly scattered (indoor) wireless channel by using multiple transmit and receive antennas. In this paper, a new SDM technique, called Maximum Likelihood Decoding (MLD) is proposed...