Extended k-u Fading Model in mmWave Communication: Statistical Properties and Performance Evaluations

Abstract

In this paper, we present a novel small-scale fading model, named the extended k-u model, which incorporates the imbalance of multipath clusters by adding a new parameter based on the original k-u model. The extended k-u model has more accurate modeling capability than the extended η-u model in scenarios with line-of-sight (LoS) paths. Additionally, it is mathematically more tractable than the a-k-η-u model. The extended k-u model provides an effective channel modeling tool for millimeter (mmWave) LoS scenarios. Through theoretical derivations, we obtain closed-form expressions for the key statistical characteristics of this model, including the probability density function, the cumulative distribution function, moments of arbitrary order, and the moment generating function. Based on these statistics, this study further derives and analyzes the expressions for some performance metrics of the communication system, including the amount of fading, the probability of outage, the average bit error rate, and the effective rate. Using the measured fading data extracted from literature, which cover communication scenarios at 28 GHz, 65 GHz, and 92.5645 GHz with LoS paths, we apply the proposed model in mmWave scenarios and compare it with the k-u model and the extended η-u model. The results show that the extended k-u model has better capability in characterizing such fading than the other two models, verifying that this extension enhances its ability to model LoS mmWave scenarios.