In OFDM systems, in-phase and quadrature (I/Q) imbalances generated in the analog front-end introduce interchannel interference and, consequently, error performance degradation. This paper provides an exact expression involving the twodimensional (2-D) Gaussian Q-function for the error probability of an arbitrary 2-D modulated OFDM signal with I/Q imbalances in frequency-flat Rayleigh fading ch...

Abstract  In this paper, the bit error rate of a recently proposed modified minimum mean squared error (MMSE) detector in Rayleigh flat fading channels is improved. It is also shown that the new detector is less sensitive to changes in the number of users. This improved detector is then adapted for use in a Rayleigh faded frequency-selective channel. An asynchronous binary phase shift keying (...

The analytical bit error rate of hierarchical quadra5 ture amplitude modulation formats, which include uniform and 6 nonuniform constellations, over flat Rayleigh fading environments 7 is studied in this paper. The analysis takes into account the effect 8 of imperfect channel estimation and considers diversity reception 9 with both independent identically and nonidentically distributed 10 chann...

OFDM system is promising technology for high speed data communication in wireless media. In this paper OFDM system model is developed over flat fading channel with Additive Gaussian White Noise (AWGN). Initially BER analysis is carried out in OFDM system with the number of sub-carriers ‘N’ using M-ary PSK and M-ary QAM. Analysis is carried out with the number of sub-carriers (N=64) with Rayleig...

Cooperative communication through decode and forward (DF) relaying is an effective solution for mitigating channel fading in wireless systems. We consider a cooperative diversity system having a source, a relay, and a destination. The source and the relay cooperate through the DF protocol to enable the transmission of a binary phase-shift keying symbol in a flat Rayleigh fading environment. The...

We describe Wireless Network Utility Maximization, WNUM, and compare its performance to traditional NUM along the dimensions of rate, delay and reliability under flat fading. Both coded and uncoded links are considered as are networks of interfering links. In each case, WNUM is shown to offer superior performance in simulations operating under Rayleigh fading. WNUM uses optimal policies to adap...

This paper analyzes an influence of an imperfect symbol timing estimate on the space-time coded modulation error performance. We use a concept of the self-noise to describe this influence. We derive an expression for the white self-noise approximation in slowly and fast Rayleigh flat fading MIMO channel. The self-noise is shown to cause a substantial performance degradation which is emphasized ...

A Joint source-channel coding (JSCC) scheme for SPIHT coded image transmission over OFDM systems with spatial diversity is proposed where no feedback channel is available. By using diversity techniques, the fading effects can be dramatically decreased and we show that subchannels in OFDM systems are indeed flat Rayleigh fading channels and approach Gaussian noisy channels when the diversity gai...

In this paper we present an analytical approach to evaluate the M-QAM symbol error rate (SER) of Alamouti space time coded OFDM direct conversion receivers subject to carrier frequency offset (CFO), channel estimation errors, outdated channel state information, limited ADC resolution and flat receiver I/Q imbalance in Rayleigh time and frequency selective fading channels. The SER is numerically...

In this paper, modulation diversity (MD) for Rayleigh fading intersymbol interference (ISI) channels is proposed. In particular, the achievable performance with MD is analyzed and a design criterion for MD codes is deduced from an upper bound on the pairwise error probability. This design rule is similar to the well–known design rule for MD codes for flat fading and does not depend on the power...