Fading distribution

About: Fading distribution is a research topic. Over the lifetime, 5732 publications have been published within this topic receiving 114193 citations.

Performance of Multihop Relay Systems with Co-Channel Interference in Rayleigh Fading Channels

Abstract: In this letter we investigate the effect of co-channel interference on the performance of multihop transmission systems that employ amplify-and-forward relays and operate in a Rayleigh fading environment. We assume that an arbitrary number of interferers with arbitrary powers are present at each relay node and derive useful bounds for important performance measures, such as the outage probability and the average symbol error probability of various digital modulation schemes.

Effects of carrier phase error on EGC receivers in correlated Nakagami-m fading

Abstract: The effects of incoherently combining on dual-branch equal-gain combining (EGC) receivers in the presence of correlated, but not necessarily identical, Nakagami-m fading and additive white Gaussian noise are studied. Novel closed-form expressions for the moments of the output signal-to-noise ratio (SNR) are derived. Based on these expressions, the average output SNR and the amount of fading are obtained in closed-form. Moreover, the outage and the average bit error probability for binary and quadrature phase-shift keying are also studied using the moments-based approach. Numerical and computer simulation results clearly depict the effect of the carrier phase error, correlation coefficient, and fading severity on the EGC performance. An interesting finding is that higher values of the correlation coefficient results to lower irreducible error floors.

Performance of FM-DCSK communication system over a multipath fading channel with delay spread

Abstract: Multipath performance is an important consideration for chaos-based communication systems. In this paper the performance of the FM-DCSK communication system over a two-ray independent Rayleigh fading channel is evaluated by computer simulations. The low-pass equivalent model of the FM-DCSK system is considered. Based on this model, we analyze the bit error performance and the effects of system parameters on the bit-error performance.

Energy-based Modulation for Noncoherent Massive SIMO Systems

Abstract: An uplink system with a single antenna transmitter and a single receiver with a large number of antennas is considered. We propose an energy-detection-based single-shot noncoherent communication scheme which does not use the instantaneous channel state information (CSI), but rather only the knowledge of the channel statistics. The suggested system uses a transmitter that modulates information on the power of the symbols, and a receiver which measures only the average energy across the antennas. We propose constellation designs which are asymptotically optimal with respect to symbol error rate (SER) with an increasing number of antennas, for any finite signal to noise ratio (SNR) at the receiver, under different assumptions on the availability of CSI statistics (exact channel fading distribution or the first few moments of the channel fading distribution). We also consider the case of imperfect knowledge of the channel statistics and describe in detail the case when there is a bounded uncertainty on the moments of the fading distribution. We present numerical results on the SER performance achieved by these designs in typical scenarios and find that they may outperform existing noncoherent constellations, e.g., conventional Amplitude Shift Keying (ASK), and pilot-based schemes, e.g., Pulse Amplitude Modulation (PAM). We also observe that an optimized constellation for a specific channel distribution makes it very sensitive to uncertainties in the channel statistics. In particular, constellation designs based on optimistic channel conditions could lead to significant performance degradation in terms of the achieved symbol error rates.

Performance of cellular CDMA with cell site antenna arrays, Rayleigh fading, and power control error

Abstract: The performance of code-division multiple-access (CDMA) systems is affected by multiple factors such as large-scale fading, small-scale fading, and cochannel interference (CCI). Most of the published research on the performance analysis of CDMA systems usually accounts for subsets of these factors. In this work, it is attempted to provide a comprehensive analysis which joins several of the most important factors affecting the performance of CDMA systems. In particular, new analytical expressions are developed for the outage and bit-error probability of CDMA systems. These expressions account for adverse effects such as path loss, large-scale fading (shadowing), small-scale fading (Rayleigh fading), and CCI, as well as for correcting mechanisms such as power control (compensates for path loss and shadowing), spatial diversity (mitigates against Rayleigh fading), and voice activity gating (reduces CCI). The new expressions may be used as convenient analysis tools that complement computer simulations. Of particular interest are tradeoffs revealed among system parameters, such as maximum allowed power control error versus the number of antennas used for spatial diversity.