Ergodic Capacity for the SIMO Nakagami- Channel

This paper presents closed-form expressions for the ergodic channel capacity of SIMO (single-input and multiple output) wireless systems operating in a Nakagami- fading channel. As the performance of SIMO channel is closely related to the diversity combining techniques, we present closed-form expressions for the capacity of maximal ratio combining (MRC), equal gain combining (EGC), selection combining (SC), and switch and stay (SSC) diversity systems operating in Nakagami- fading channels. Also, the ergodic capacity of a SIMO system in a Nakagami- fading channel without any diversity technique is derived. The latter scenario is further investigated for a large amount of receive antennas. Finally, numerical results are presented for illustration

Simple closed-form channel capacity formulas for the SIMO Nakagami channel

This paper presents simple closed-form expressions for the ergodic channel capacity of SIMO (single-input and multiple output) wireless systems operating in a Nakagami fading channel. As the performance of SIMO channel is closely related to the diversity combining techniques, we present close form expressions for the capacity of maximal ratio combining (MRC), equal gain combining (EGC) and selection combining (SC) diversity systems for Nakagami fading channels. Also for the first time in international literature, the ergodic capacity of a SIMO system in a Nakagami fading channel with none diversity combining technique applied, is derived. Finally numerical results are presented for illustration

A small scale fading model with sectored and three dimensional diffuse scattering

In frequency non-selective fading channels the multipath components can arrive at the mobile receiver via a three dimensional (3-D) scattering mechanism. That case occurs especially in urban environments, in which the tall buildings and other obstacles cause an arrival of multipath energy in the elevation plane, besides that arriving in the azimuth one. Another issue, which is a matter of investigation, is that the multipath energy may arrive at the mobile receiver in specific angular sectors. This is caused when a part of energy is blocked by the channel obstacles, or no multipath energy arrives from certain directions, due to lack of scattering objects in those directions, or directional antennas are employed. In this paper we propose a model which takes into account both 3-D multipath scattering and partial arrival of multipath energy. The proposed model assumes that the multipath components arrive at specific angular sectors in the azimuth receiver's plane, whereas in the elevation plane the angles of arrival are of continuous nature. Moreover a specular component with constant amplitude also exists. From the closed form autocorrelation function, the Doppler power spectral density (PSD) of the model is analytically derived Afterwards the probability density function (PDF) of the envelope and phase are analytically calculated. What follows are the second order statistics, level crossing rate (LCR) and average duration of fades (ADF's), in closed form

On the Scatterers' Mobility and Second Order Statistics of Narrowband Fixed Outdoor Wireless Channels

In this paper, we study the temporal behavior of narrowband fixed outdoor wireless channels by modeling the impact of scatterers' mobility on the second order statistics of such channels. We show that the Nakagami-m, gamma, Weibull and lognormal probability density functions (PDFs) can adequately approximate the scatterers' mobility at outdoor environments by comparing the theoretically derived autocorrelation functions (ACFs) with measured ACFs. These theoretical ACFs arise after considering several candidate PDFs for the impact of scatterers mobility. We select that PDF whose ACF provides the best fitting to measurements. The modeling of scatterers' mobility lead us to present analytical expressions for the level crossing rate (LCR) and average fade duration (AFD) together with an exact expression for the power spectral density (PSD)

A deterministic simulation model for sojourn time in urban cells with square street geometry

A deterministic simulation model for the calculation of sojourn time statistics is proposed. The model is designed for urban cells taking into account city movement in street pattern, traffic lights, and crossings. Sojourn time and remaining sojourn time are assumed to be random variables that follow a gamma distribution. The parameters of gamma are found for a range of the chosen cell parameters (road length, probability of stopping at a crossing and cell radius) using Monte Carlo simulation. Then, the values are fitted to the empirical model using genetic algorithms with grammatical evolution. The model can be used to calculate sojourn time statistical parameters for any urban circular cell with square street pattern