In this paper, we introduce our millimeter-wave (mmWave) radio channel measurement for integrated sensing and communication (ISAC) scenarios with distributed links at dual bands in an indoor cavity; we also characterize the channel in delay and azimuth-angular domains for the scenarios with the presence of 1 person with varying locations and facing orientations. In our setting of distributed links with two transmitters and two receivers where each transceiver operates at two bands, we can measure two links whose each transmitter faces to one receiver and thus capable of line-of-sight (LOS) communication; these two links have crossing Fresnel zones. We have another two links capable of capturing the reflectivity from the target presenting in the test area (as well as the background). The numerical results in this paper focus on analyzing the channel with the presence of one person. It is evident that not only the human location, but also the human facing orientation, shall be taken into account when modeling the ISAC channel.

Stored channel measurement can be utilized for developing site-specific radio channel emulator with high accuracy. The channel emulator is expected to synthesize temporal fading characteristic in terms of a time-variant channel impulse response (CIR) of the mobile station (MS) at any position in space. However, such continuous characteristics is hard to acquire directly from the measurement because only a set of discrete CIR samples could be sparely-captured. In this work, interpolation technique based on ensemble Kalman filter (EnKF) is proposed to reconstruct the continuous CIR profile given a sequence of undersampled measured CIRs. The proposed EnKF model was utilized to estimate and track fading parameters between two adjacent measured CIR. The interpolated CIR is then computed from those estimated parameters. Through experiment, performance of EnKF-based interpolation is evaluated in the simulation using 3GPP channel model. The advantage and limitation of the proposed interpolation scheme is discussed based on the simulation result.

In recent years, with the spread of local networks such as IoT services and local 5G, the desire to do radiowave propagation simulations are increasing. For indoor environments, creating a digital simulation model can be a burden for the user. This paper proposes a method to reconstruct the indoor model with objects from 3D point cloud data for ray tracing simulations. To test the usability of the reconstructed model, simulation results were compared with channel sounding measurements. The results gave good agreement and implied that our proposed method can be used to make indoor models for ray tracing simulations.

Nowadays, various kinds of information and communications technology (ICT) systems have been developed and utilized in our life as social infrastructure. And recently, the cyber-physical system (CPS) is gathering great attention for enhancing system development. In the CPS, the physical environment information is imported to the emulator, and the communication performance is evaluated based on the radio propagation simulation. In dynamic environments such as intelligent transport systems (ITS) and smart office systems, many workers and autonomous robots are working together, and they cause serious fluctuation in the radio propagation channel. This paper proposes the propagation simulation method in those dynamic environments. The environment change is analyzed by continuous measurements of LiDAR, and the dynamic radio propagation channel behavior is simulated based on the ray-tracing algorithm and the knife-edge diffraction theory. The simulation result were compared to the result of radio propagation measurement in the 28 GHz band in an exhibition space of the office, and it showed a fair agreement. The proposed method is expected to be utilized for the ICT system development in dynamic environments.

This paper establishes the analytical model and analyzes the statistical behaviors of multimode channels in spherical vector wave (SVW) domain based on the microcellular radio channel measurement in downtown Helsinki at 5.3 GHz band. The multimode channel is the representation of radio wave propagation in the form of the SVW mode coupling between the transmit and receive antennas. The multimode channel does not rely on particular realizations of antennas at link ends, since any transmitting/receiving/scattering fields associated with an antenna can be modeled as a weighted sum of SVW modes where different antennas have different mode weights. The multimode channels are converted from the plane wave channel model parameters that are extracted from measured channels of coherent snapshots along 6 different routes in Helsinki. Based on the analysis of various first and second order statistics of the multimode channels, the main findings can be summarized as follows: 1) the multimode channels are power imbalanced; 2) the envelope short-term fading statistics of the multimode channels can be described with Rician probability distributions with varying K-factors; 3) the auto-correlations of multimode channels along the spatial translation of a mobile node in a propagation environment present varying coherent distances; 4) the cross-correlations of multimode channels vary with the spatial translation too. The obtained results and the proposed multimode channel model provide invaluable insights into the design of antenna systems tailored to a specific propagation environment. Indeed, antenna systems at both link ends can be devised such that the multimode channels with higher power, larger coherent distance and smaller cross-correlation are excited resulting in multiple-input multiple-output antenna systems that exploit efficiently the degrees of freedom of the propagation channel.

This paper investigates a transmission power control scheme based on the context-specific temporal correlation model in WBAN. Firstly construction of the context-specific temporal correlation model is presented. After that a channel estimation method using the last known channel gain and the constructed temporal correlation model is explained. The channel estimation is then used in our proposed transmission power control scheme, that determines the transmit output power of each transmission. Performance of the transmission power control is illustrated using the Castalia simulator. A guideline of parameter tuning that trades off between communication reliability and energy consumption is also given. Furthermore, the effectiveness of the transmission power control scheme is compared to the fixed transmit power at −5 dBm. From the simulation results, applying the transmission power control scheme reduced the energy consumption up to 12.4 percent and yielded a slightly higher packet reception rate when the packet rate was not oversaturated. When the packet rate was oversaturated, the transmission power control scheme reduced 14.2 percent of the energy consumption with less than 0.06 percent of increase in a packet error rate.

This paper presents measurement and analysis results of power delay profiles and fading characteristics for “Public Broadband Wireless Communication (PBB) System” in VHF band. The PBB system was proposed to utilize a portion of vacant spectrum in VHF band due to the frequency reallocation plan in Japan, and the system was standardized as ARIB STD-T103 as well as IEEE802.16n. The purpose of this study is to evaluate the applicability of the system for non-line-of-sight urban environment and characterize the 200 MHz band broad band radio channel. The measurement is conducted by using a developed device which is compliant with the ARIB STD-T103 as a transceiver, and received signal is captured as complex IQ signals by using a signal analyzer. In order to obtain the power delay profile, impulse responses are analyzed by calculating sliding correlation between reference signal and measured signals. For the evaluation of delay characteristics, RMS delay spread is calculated using the power delay profile. In addition, fading characteristics is also shown to confirm the behavior of VHF band mobile propagation channel.

In next-generation mobile communication systems, utilization of higher frequency bands above 10 GHz has become a hot research topic because it has the potential to improve network capacity drastically by utilizing the available wideband spectrum. However in the higher frequency bands, in addition to the higher propagation loss, diffuse scattering of propagation wave is thought to affect the multiple-input multiple-output (MIMO) channel characteristic more significantly. In this paper, 11 GHz band MIMO channel measurements were conducted in a line-of-sight (LoS) indoor environment to clarify the characteristics of diffuse scatterings in the higher frequency band. The frequency, angular, and the polarization domain dense multipath component (DMC) propagation parameters were estimated by using the RiMAX-based estimator. The measurement result shows that there was a significant DMC due to diffuse scatterings from the floor and the ceiling. The DMC had directional and polarization dependencies that were different from the RiMAX DMC model. The result is expected to be utilized for the novel MIMO channel model proposal in the higher frequency band that includes the DMC contribution.

To use millimeter wave bands in future cellular and wireless networks, characterization of the radio propagation channel in outdoor urban small cell or pico cell environment is vital. In this paper we present results from analysis of wideband full polarimetric directional channel measurements in an urban pico-cell environment using the double directional millimeter wave channel sounding system we developed. Multipath clusters with excess gain ranging from −9.6 dB to −22 dB in both line of sight (LOS) and obstructed LOS cases are seen. The most significant clusters were due to first and second order reflection, and diffraction. The clusters ranged from being highly specular in nature with very small (nearly 0°) angular spread to having angular spreads of up to 5.8° in azimuth and 6.3° in elevation. Similarly the delay spread of the clusters ranged up to 2.1 ns.

This paper presents a wideband full polari-metric directional channel measurement results at 58.5 GHz in a small office room environment assuming an indoor access-point (AP) scenario in the next generation mobile systems. The delay resolution was 2.5 ns from the signal bandwidth of 400 MHz, and the double directional angular characteristics were achieved by rotating high gain horn antennas at both sides of transmitter and receiver. By identifying scattering objects from the measurement data analysis, some important observation about the channel properties were reported. The results reveal that there were a few number of dominant specular multipath components of which the relative power to that of the direct path ranged between -8 and -13 dB. It was also observed that the depolarization is not significant in most of the detected paths with cross-polarization ratio of larger than 14 dB.

Wireless body area networks (WBANs) are an emerging technology for realizing efficient healthcare and remote medicine for the aging society of the future. In order to improve the reliability of WBAN systems and support its various applications, channel modeling and performance evaluation are important. This paper proposes a simulation-based channel modeling for evaluating the performance of WBAN cooperative transmission schemes. The time series of path losses among seven on-body nodes are generated by the finite-difference time-domain method for seven body motions. The statistical parameters of the path loss for all the motions are also obtained. The generated path loss is then applied to the evaluation of the two-hop decode-and-forward relaying scheme, yielding an improvement in transmit power. From the evaluation of body motion, useful insights are obtained such as which relay links are more robust than others. Finally, the proposed approach is validated through comparison with a measurement-based approach.

This paper presents a frame based contention resolution algorithm that can be systematically applied for random access protocols under different assumption of feedback types which include binary, ternary and known multiplicity feedbacks. We introduce two new algorithms that can effectively utilize feedback information to resolve packet collisions. Based on extensive simulation results, the achievable delay performance is shown to be highly dependent upon the amount of feedback information available to each user and how the feedback information is used in contention resolution. Multiplicity feedback in particular where the information about number of accessing packets is available, significant improvement in average delay can be achieved compared to binary and ternary feedbacks.

This paper addresses the issue of MIMO channel estimation with the aid of a rough estimate of temporal correlation statistics where MIMO antenna selection system is employed. Under the temporally correlated channel, proposed method controls allocation of length of training symbols for each antenna element so that the elements which are likely to be selected are estimated more precisely than the other elements. In order to utilize this estimation scheme effectively, this paper also proposes the antenna selection method which takes account of a difference of channel estimation accuracy among antenna elements. When the ML channel estimation was adopted, the proposed selection method is with almost the same computational cost as the conventional selection methods. The proposed method does not rely on spatial correlation statistics which is not always stable in real propagation scenarios. The numerical simulation using 3GPP-SCM revealed that the proposed method works effectively under shorter training symbols employed.

Wireless Body Area Networks (WBANs) are allowed to be applied in medical and non-medical fields. In this paper we present a prioritization mechanism for emergency case in both medical and non-medical WBANs applications. The main idea of this mechanism is to allow highest priority nodes or nodes of emergency to get the channel immediately at the expense of low priority nodes. This mechanism postpones the reservation of low priority nodes until the all high priority nodes are resolved. We apply a collision resolution protocol, tree algorithm, to achieve our goal. It can be observed from the simulation results that tree algorithm allows high priority nodes to get the channel first without contending with the low priority ones.

On-body communication channels are gaining increasing interests as more and more wireless devices are wearable in the fields of medicine, military, and personal communications. This paper presents an experimental investigation of the dynamic features of time-varying on-body channels with continuous movements of human body. Channel response at 10 antenna positions in two dynamic scenarios, walking and standing up and sitting down, have been measured in the anechoic chamber. Based on the statistical analyses of fading duration, a five-state Fritchman model that considers channel dwelling time at a given quality is proposed. Parameters of the Fritchman model are estimated from the measured data. The characteristics of simulated burst channels are in good agreement with the measurements.

Precision ultra-wideband (UWB) ranging requires accurate estimation of time-of-arrival (ToA). The threshold-based ToA estimation is attractive due to its simplicity. In this paper theoretical closed form expressions of ToA estimation error are derived. A new technique to set the threshold as a function of distance is proposed. ToA estimation error of conventional threshold and distance dependent (DD) threshold setting are analyzed at various signal-to-noise ratios (SNR).

As a growing interest in the cognitive radio technology has been taken based on the idea of opportunistic spectrum use, the spectrum sensing technique for dynamic channel environment is more and more important to ensure that cognitive radios would not interfere with primary systems while it achieves reasonable throughput opportunistically. Architecture based on filter bank allows to sense multi-channels simultaneously with low spectrum leakage from adjacent channels thanks to efficient implementation of bandpass filters. Therefore it is now attracting much interest. In this paper, we propose a framework of multi-channel sensing architecture based on polyphase DFT filter bank followed by energy detector with minimum complexity. The sensing performance is evaluated by numerical simulation as well as theoretical analysis comparing with the conventional periodogram spectral estimator and time domain sequential sensing.

This paper presents clusterwise polarization characteristics based on an estimated MIMO channel of a small urban macrocell at 4.5 GHz. Polarization path gain, cross-polarization ratio, and co-polarization ratio characteristics as influenced by channel parameters such as delay, azimuth and elevation angle of arrival were investigated. Hypothesis testing was used as a verification of the results. This statistical verification clarifies the independence of polarization characteristics from an azimuth angle of arrival, whereas some correlation was found between the cross-polarization ratio and the elevation angle of arrival. The results also confirmed a log-normal cross-polarization ratio.

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.

This paper presents a radio frequency (RF) controlled spatial fading emulator for the evaluation of a handset MIMO antenna. The RF-controlled fading emulator can control RF signals directly in the spatial domain to produce an accurate radio propagation channel model, which includes the uniform and non-uniform angular power spectra (APS) in the horizontal plane. Fading correlation and MIMO channel capacities of a quasi-dipole array, in the case of up to three spatial clusters, are measured by using the emulator. From agreement between the measured data and theoretical values, the effectiveness of the emulator was confirmed.

Multi-Input-Multi-Output (MIMO) is an emerging technology for the 4th-generation mobile communication systems due to the capability of high-speed data transmission. There have been only a few literatures regarding MIMO propagation characteristics under outdoor condition, and most of which have focused only on 2 GHz bands for existing cellular systems. However, since 3.4-3.6 GHz band will be allocated as one of frequency bands for the 4th-generation mobile communication systems, the channel characteristics at this band should be carefully considered. This report presents the outdoor MIMO channel characteristics measured by a 2×2 MIMO channel sounding system at the center frequency of 3.35 GHz in urban environment. In this measurement system, the 9-stage PN signals are transmitted by controlling the transmission timing in each transmitter, and hence, the complex MIMO channel impulse responses can be obtained by using same PN sequence in the receiver. From the measured MIMO channel characteristics, we computed the channel capacity based on each eigenvalue that was obtained through singular value decomposition (SVD). In addition, we evaluated the channel capacity for line-of-site (LOS) and non-line-of-site (NLOS) environments with respect to the antennas distance.

This paper describes experimental results of an antenna selection system that is applied to a receiver side of multiple- input multiple-output (MIMO) systems. We proposed an antenna selection system that each MIMO receive branch has different polarization and directional pattern antennas and selects one antenna combination by using radio frequency micro electro mechanical system (RF-MEMS) switches. A 2 x 2 MIMO -OFDM transmission system is constructed to evaluate the performance of the proposed antenna selection system, which can not only measure real-time bit error rate (BER) but also control the antenna switch based on an antenna selection algorithm. BER measurement experiments were conducted in an indoor office environment, and it was found that more than 3 dB receive power improvement was achieved with the proposed antenna selection system comparing to the vertical polarization fixed receive antennas from the result of the averaged BER performances.

This paper describes a real-time performance evaluation of a receive antenna selection method for a spatial multiplexing multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system in a real environment. In this real-time performance evaluation, we employed a receive antenna selection method to select a suitable set of polarization antennas at the receiver side of the MIMO-OFDM system with low computational complexity. The receiver of the MIMO-OFDM system caught the preambles of the signal bursts to calculate the channel impulse responses and used them in calculating a cost function to decide a suitable set of polarization antennas. The results showed that the MIMO- OFDM system with the receive antenna selection method selected suitable sets of polarization antennas and achieved good performance.

This paper investigates the applicability of deterministic ultra wideband (UWB) propagation modeling for evaluating UWB system performances. The modeling explores the wave propagation characteristics on both transmitting and receiving antenna sides, which is known as the double directional modeling. In evaluating the applicability, bit error probability (BEP) performances were derived using two kinds of channel impulse responses: 1) raw data which were measured by channel sounding campaign and 2) reconstructed data from the propagation modeling results. In the BEP simulation, the direct sequence UWB system was considered. Comparison of the BEP performances from two kinds of channels revealed that the concept of the double directional modeling was capable of evaluating BEP performances accurately. However, it was also found that the limitation of our double directional modeling approach based on the model-based ray path extraction method resulted in the limited capability in modeling the total received power. As a consequence, fading statistics of the reconstructed channels were different from the measured data, ending up with less accuracy to predict BEP performances depending on the data rate. Finally, possible solutions to improve the double directional propagation modeling were suggested.

This paper proposes a receive antenna selection method for a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with Micro electro mechanical systems (MEMS) switches and polarization antennas at receiver side, taking into consideration low computational complexity. The proposed method selects a suitable set of polarization antennas which gives lower correlation between received signals, larger received signal power and higher signal- to-interference-plus-noise power ratio (SINR), therefore, achieves a lower bit error rate (BER). We use measured channel data to evaluate the performance of the proposed method and show that the it works effectively for the realistic channel.

In this paper, the prediction of received power in the out-of-zone of a dedicated short range communications (DSRC) system operating inside a typical arched highway tunnel is discussed. By conducting wideband directional channel sounding inside the tunnel, the gain, angle-of-arrival and delay of each propagation path are estimated by means of a multidimensional maximum likelihood estimation algorithm from the measured data. Using these estimated parameters and by employing simulations of application antennas according to the DSRC standard, the received power in the out-of-zone is predicted for 2 roadside unit (RSU) antenna positions. The dominant scatterers causing the over-reach of radiated power to the out-of- zone were identified and attributed to the ground and sidewalk. These scatterers can affect the received power level in the out- of-zone by as much as 10 dB. It can therefore be concluded that suppressing ground and sidewalk scatterings in the vicinity of RSU by installing composite pavement materials are needed to increase the electromagnetic absorption in order to guarantee DSRC services.

To analyze the radio propagation channel inside a tunnel, a wideband directional measurement campaign was managed inside an arched tunnel which was constructed to be used for a highway. Using a wideband channel sounder equipped with a cylindrical dual polarized array at the receiver (Rx), the spatio-temporal characteristics of the received propagation paths could be estimated by means of a super-resolution estimation algorithm. The dominant scatterers are classified into 5 classes based on the structure of the tunnel as follows: ceiling, light-frames, walls, sidewalk or ground. The power contribution and cross polarization ratio for different Rx positions along the tunnel are compared

A channel model for line-of-sight (LoS) small street microcell in dense urban areas is proposed. The scattering power distribution (SPD) in the channel seen from the receiver (Rx) based on the physical phenomenon is obtained. The coefficients of the distribution are derived by approximation to a set of urban street microcell measurement data. The azimuth-power spectrum (APS) for the proposed model is compared to those for conventional elliptical model as well as to the experimental results obtained from measurements in three different streets of a dense urban area. It is shown that the proposed model in contrast to the conventional models produces results that closely agree with the experimental results

Performance of a multiple input/multiple output (MIMO) system is largely degraded when it is equipped in mobile terminals or placed near a human body because radio waves are absorbed or shielded by the human body. This paper evaluates an antenna selection-based MIMO system under environments near human body. Each MIMO antenna branch at the receiver of the proposed MIMO system is equipped with several antennas, which have different characteristics such as polarizations and directional patterns, and the receiver selects one of them by radio frequency (RF) switches. A 2times2 MIMO propagation measurement at an indoor environment with the proposed antenna is conducted, and channel capacities and bit error rates (BERs) are evaluated by computer simulations with the measured channel data. From the results, the channel capacity is improved by more than 1.5 bit/sec/Hz when the proposed antenna is used near a human body. In addition, from the BER simulations that assume OFDM transmission IEEE802.11n, it is found that the received power is improved by more than 5 dB at cumulative distribution function (CDF) value of 0.5.

A real-time multiple-input multiple-output (MIMO) channel measurement system was implemented by using a 4times4 MIMO software defined radio (SDR) testbed. A target application of this system is to evaluate realistic performance of closed-loop MIMO transmission in time-varying channels at 5 GHz band. The results of indoor measurements showed that feedback delay of the closed-loop transmission causes severe degradation of channel capacity, and an interference canceller in eigenbeamspace is indispensable in achieving the benefits of channel state information (CSI) feedback

Space-time (ST) equalizer and delay diversity transmission (DDT) were field tested in uplink for a time-division multiple-access mobile communication system. The ST equalizer used a cascade connection of constrained array processors and branch-metric-combining (BMC) maximum-likelihood sequence estimation which was designed to provide both space- and path-diversity gains from first-arrival and one-symbol-delay paths while suppressing excessive intersymbol interference. DDT with two antennas was used for the mobile transmitter to ensure sufficient path diversity at the ST equalizer in a small-delay-spread environment. Test results showed that the ST equalizer bit error rate (BER) was significantly better than an ST equalizer without BMC and a single array processor for both micro- and macrocell environments. Furthermore, the ST equalizer BER with DDT was better than that without DDT for the microcell environment.

This paper presents multipath characteristics of non-specular scattering from building surface roughness. Superresolution method was applied as an approach to handle signal parameters (DOA, TOA) of the individual incoming waves reflected from building surface roughness. In order to comprehend in detail the microscopic mechanisms of scattering, signal parameters are to be incorporated into the geometrical ray tracing. The results show that the multiple paths can he detected from many scatterers, such as ground, window glass, window frame, bricks surface, as well as directly from the transmitter. Most of the scattered waves arrives closely from specular directions.

This report presents a MIMO sounding system dedicated to short range wireless communication. The system can easily be integrated with a vector network analyzer (VNA) and other commercial equipments. The advantage of our proposed system is the achievement of completely automatic measurement, while retaining accuracy. Using the system, a double directional measurement campaign in indoor NLOS environment was performed, where the channel was estimated in a deterministic way with the ISI-SAGE algorithm. In the use of ISI-SAGE algorithm, we propose to estimate polarization characteristics for identical path. One of the realizations of the optimum search and initialization with successive interference cancellation type procedure, which is suitable for a large number of sampling, available case is shown as well. The result of the measurement campaign shows the effectiveness of our proposals.

Measured wideband direction-of-arrival data from urban macrocellular environment were clusterized. The clusterization was done by manual inspection. To understand the physical propagation channel, the source points of the extracted clusters were located to the local environment surrounding the mobile station. Some key parameters were calculated for each of the extracted clusters and for the residual power. By combining these parameters with the estimates of the cluster source points, assumptions on the propagation mechanisms of the clusters were drawn. According to the results the most significant sources are building structures above the average building height and corners of the buildings. This result is inline with previous studies in the urban propagation. Only a few significant clusters were found, in this study three clusters out of 14 extracted clusters contributed nearly 60% of the received power, while 19% of the power remained outside the clustering. Most of the clusters follow the Rician distribution with relatively high K-factor, while the residual power was Rayleigh distributed. There was only slight depolarization from the transmitted vertical polarization. One of the clusters was a clear exception with a negative XPR.

Field test of space-time (ST) equalizers for combating intersymbol interference (ISI) at base stations, was conducted in microcell and macrocell environments in central Tokyo area. Test results indicate that the ST equalizers provide significantly better bit error rate (BER) than an array processor alone does, due to both space and path diversity while suppressing the long-delayed path. Furthermore, a delayed diversity transmission (DDT) in a small delay spread environment provides sufficient delay-spread and improves the BER of the ST equalizer.

This paper reports a spatio-temporal channel characterization of a suburban non-line-of-sight microcellular environment in which azimuth-delay profiles obtained by an experiment are compared with ray-tracing simulation. The results are statistically treated step by step to extract model parameters in order to characterize the spatio-temporal channel. The experimental results we obtain are used to improve the accuracy of the simulation process. We are able to obtain a very good agreement between the simulation and the experiment, with the exception of the exponential decay of the delay profile. The results presented can be directly used to implement the stochastic spatio-temporal channel model, based on the deterministic ray-tracing simulations.

In a high bit rate indoor wireless communication system, i.e. wireless LAN, the inter-symbol interference (ISI) due to the multipath delayed waves much degrades the communication quality. This paper presents a BER floor simulation for the indoor multipath environment. The room is modeled as a rectangular box composed of dielectric walls, and multiple reflections are modeled as images of the source on the walls (Manabe et al., 1996). Wave polarization is carefully treated for higher accuracy of estimation. After multipath channel estimation, the equivalent transmission-path model (Karasawa et al., 1997) is introduced to simplify the BER floor estimation. Some results for different polarisation and different base station positions are compared, to find out the optimum design of the antenna properties.