Performance evaluation of mm wave single carrier systems with a novel NLOS channel model

In this paper, we evaluate the performance of a low-complexity 60 GHz system in a realistic non-line-of sight indoor environment. We consider a single-carrier transmission system that does not employ equalization, but only uses forward error correction. The channel model was created from measurements in a conference room in which a non-line-of-sight environment is created through a human-sized blocking object, and in which beamforming is applied at the receiver to track and obtain reflected paths. We obtained the bit error rate performance using channel impulse responses obtained from measurements and from the resulting channel model. Our evaluation indicates that the system can achieve the target bit error rate. As a result, we not only verified the new channel model but also show that complex equalization methods are not necessary to achieve reliable communication in indoor 60 GHz scenarios

BIC-based optimization of the identification of multipath propagation clusters in MIMO wireless systems

A novel framework to optimize the identification clustering of multipath scatterers in a MIMO wireless system is proposed. It is a comprehensive evaluation of major cluster identification methods across multiple categories of clustering methodologies. The reliability will be ensured with the use of a parameter selection framework utilizing the Bayesian Information Criterion (BIC). Statistical preprocessing with support vector decomposition and normalization will also be handled. © 2016 IEICE

Wideband nulling capability estimate of a tapped delay line beamformer

We attempted to quantify the maximum number of wideband interference signals that can be sufficiently nulled under severe interference scenarios, using a tapped delay line beamformer with a fixed number of antenna elements (M). Evaluation of simulation results shows that for increasing the fractional bandwidth, more taps are needed, but to a certain limit. In addition, the results show that the maximum number of wideband interference signals that an array can sufficiently null with the minimal number of taps may not improve beyond M-2

Mobile station spatio-temporal multipath clustering of an estimated wideband MIMO double-directional channel of a small urban 4.5 GHz macrocell

Multipath clusters in a wireless channel could act as additional channels for spatial multiplexing MIMO systems. However, identifying them in order to come up with better cluster channel models has been a hurdle due to how they are defined. This paper considers the identification of these clusters at the mobile station through a middle ground approach—combining a globally optimized automatic clustering approach and manual clustering of the physical scatterers. By including the scattering verification in the cluster identification, better insight into their behavior in wireless channels would be known, especially the physical realism and eventually a more satisfactorily accurate cluster channel model could be proposed. The results show that overlapping clusters make up the majority of the observed channel, which stems from automatic clustering, whereas only a few clusters have clear delineation of their dispersion. In addition, it is difficult to judge the physical realism of overlapping clusters. This further points to a need for the physical interpretation and verification of clustering results, which is an initial step taken in this paper. From the identification results, scattering mechanisms of the clusters are presented and also their selected first and second order statistics

Polarimetric beamforming comparison of the multipath clusterization of ML estimates and the measurement data of a MIMO macrocell channel

Clusters produced by multipath clusterization were comparatively evaluated using the directional power spectrum of the measured channel, which was obtained by polarimetric beamforming due to the dual-polarized nature of the channel sounding data. The clusters were from the results of the clusterization of maximum-likelihood-based path parameter estimates of a macrocell channel. The approach provides a way to render the physical meaning of clustering results in line with the measured channel. The result shows some slight offset from the measured channel, nevertheless, the cluster locations were comparable

Clustering results of estimated MIMO double-directional channel data of a small macrocell

Using an optimized clustering approach, results of the determination of the clustering of multipaths in a wireless channel are presented. The data used were from the results of estimating the double-directional parameters of a MIMO channel sounding done in a small urban macrocell. Observations of the clustering results show that the distribution of cluster power proportion should also be taken into account when modeling clusters as unnecessary exclusion of least clusters may not represent the characteristics of clusters in the channel

Experimental study and modeling of channel parameters at mobile station in a site-specific urban macrocellular environment

This paper gives a study of 3-D channel parameters, i.e., azimuth, elevation directions at MS (DMS), and delay. Both vertical and horizontal polarizations were transmitted and received in the measurement. By observing the azimuth power spectrum density (APSD), the analysis of the spatio-temporal channel parameters including full polarimetric behaviors was conducted. Power spectrum density (PSD) models are proposed for modeling measured azimuth, elevation DMSs and excess delay PSDs. The relationship between cross-polarization ratio (XPR) and best-fit parameters is discussed. As shown in [1], the extension of the models studied here to the MIMO channel model is possible by the assumption of kronecker model of the base station (BS) and MS

Identification of relatively strong clusters in an NLOS scenario at a small urban macrocell mobile station

We present a procedure for identifying clusters around the mobile station in a small macrocell. It is based on the parameters of stronger clusters, which serve as the initial centroids. Using this method, most of the clusters were identified in an NLOS scenario. Employing this approach may aid in the identification of clusters when relatively strong paths below the path power of the centroids are included