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Recently there have been many proposals to generate a complete channel model that covers wide range of carrier frequencies and take into consideration different aspects of channel propagation statistics. Many of these models focus on two dimensional propagation, i.e. propagation in the azimuth plane only. The assumption of 2D propagation may lead to inaccurate estimation of channel capacity and system level performance. In addition, few studies have focused on the propagation characteristics in the 800 MHz band. In this paper a complete 3D channel model is generated and examined through 3D ray tracer tool. The paper proposes detailed channel related parameters for urban macro and micro-cell environments at carrier frequencies of 800 MHz and 2.6 GHz. The paper analyzes the channel in terms of best-fit normal parameters for large scale parameters, path loss models, cross-correlation of large scale parameters, and de-correlation distance for both line-of-sight and none line-of-sight conditions. The paper uses the generated statistics to extend the current 2D 3GPP/ITU channel model to 3D model and compare the propagation statistics generated by this model with the ray tracer predictions.

Abstract-To maintain a high quality of service to the increasing number of smartphone users, additional spectrum is required. The TV white space bands provide a good opportunity to achieve this goal. They can be used as standalone spectrum or aggregated with other licensed bands to increase the total available bandwidth. This paper compares the downlink throughput performance of LTE-Advanced in two different frequency bands. It also addresses the impact of smartphone orientation, with results quoted for three different elevation angles. We consider the higher LTE-Advanced band at 2.6 GHz and the TV white space band at 800 MHz. The radio channel is modelled using a state-of-the-art 3D ray-tracing tool combined with measured 3D radiation patterns for the base station and handset antennas. The throughput performance for a large number of base station and mobile terminal locations is investigated in two different UK cities. We use the computationally efficient received bit information rate algorithm to compute packet error rate as a function of channel structure and SNR. The approach reduces simulation run time by a factor of more than 300. Similar average throughput vs SNR results are observed in both frequency bands. However, higher K-factor and total received power levels are observed when the user equipment is tilted to 45º in elevation. Throughput results show that the efficiency of carrier aggregation between LTE and TVWS bands depends on the cell size and the type of urban environment.

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This article presents a comprehensive review of the principles and characteristics of three-dimensional (3D) channel models. We propose a framework for a 3D channel extension of the widely used two-dimensional (2D) 3GPP/ITU generic channel model. We describe the main components and challenges of the newly proposed 3D channel model and the motivations that lie behind them. 3D channel models specify multipath elevation angles as well as azimuth (or horizontal plane) angles. This enables the evaluation of 3D MIMO techniques such as Full Dimension (FD) MIMO and per user 3D beamforming. We also provide a state-of-the-art review on the evolution of channel models. The article ends with a discussion on the impact of 3D channel modelling on system level performance.