On the Frequency Dependency of Radio Channel's Delay Spread: Analyses and Findings From mmMAGIC Multi-frequency Channel Sounding

This paper analyzes the frequency dependency of the radio propagation channel's root mean square (rms) delay spread (DS), based on the multi-frequency measurement campaigns in the mmMAGIC project. The campaigns cover indoor, outdoor, and outdoor-to-indoor (O2I) scenarios and a wide frequency range from 2 to 86 GHz. Several requirements have been identified that define the parameters which need to be aligned in order to make a reasonable comparison among the different channel sounders employed for this study. A new modelling approach enabling the evaluation of the statistical significance of the model parameters from different measurements and the establishment of a unified model is proposed. After careful analysis, the conclusion is that any frequency trend of the DS is small considering its confidence intervals. There is statistically significant difference from the 3GPP New Radio (NR) model TR 38.901, except for the O2I scenario.Comment: This paper has been accepted to the 2018 12th European Conference on Antennas and Propagation (EuCAP), London, UK, April 201

Factors affecting the bit error rate performance of the indoor radio propagation channel for 2.3-2.5 GHz frequency band

The use of wireless in buildings based on microwave radio technology has recently become a viable alternative to the traditional wired transmission media. Because of the portable nature of radio transceivers, the need for extensive cabling of buildings with either twisted pair, coaxial, or optical fibre cable is eliminated. This is particularly desirable where high user mobility occurs and existing wiring is not in place, or buildings are heritage in nature and extensive cabling is seen as intrusive. Economic analysis bas also shown that significant labour cost savings can result by using a radio system or a hybrid mix of cable and radio for personal communication. The use of wireless systems within buildings introduces a new physical radio wave propagation medium, namely the indoor radio propagation channel. This physical medium has significantly different characteristics to some of the other forms of radio channels where elevated antennas, longer propagation path distances, and often minimally obstructed paths between transmit and receive antenna are common. Radio waves transmitted over the indoor channel at microwave frequencies behave much like light rays, they are blocked, scattered, and reflected by objects in the environment. As a direct result of this several phenomena unique to this form of physical medium become apparent, and they must be accounted for in the design and modelling of the indoor radio propagation channel transmission performance. In this thesis we analyse and characterise the indoor radio channel as a physical medium for data transmission. The research focuses on the influence of the radio physics aspects of an indoor microwave channel on the data transmission quality. We identify the associated statistical error performance for both time varying and temporally stationary indoor channels. Together with the theoretical analysis of the channel, a series of propagation measurements within buildings are completed to permit empirical validation of the theoretical predictions of how the indoor microwave channel should perform. The measurements are performed in the frequency range 2.3-2.5 GHz, which includes the 2.4-2.4835 GHz band allocated by spectrum management authorities for industrial scientific and medical radio use, (ISM band). As a direct result of our measurements, statistics related to channel noise, fading, and impulse response for the indoor microwave channel are obtained. The relationship between data transmission error statistics and the aforementioned phenomena is quantified and statistically analysed for the indoor radio channel and phase shift keyed (PSK) modulation. The results obtained from this research provide input data for the development of a simulation model of an indoor wireless mobile channel. Our measurements identify microwave ovens as a channel noise source of sufficient magnitude to corrupt data transmission in the ISM band, and an in depth analysis of the effect of noise emissions from operational microwave ovens on PSK modulation is presented in this thesis. As a result of this analysis, the estimated data error rates are calculated. Channel fading measurements provide results that will be used as the input data for the design of antennas for use on the indoor microwave channel. We also show that a data rate of eight megabits/second is possible over the typical indoor radio channel, with no requirement for adaptive delay equalisation to counter multipath signal delay spread

Mobile WiMAX system performance – simulated versus experimental results

This paper addresses the downlink performance of mobile WiMAX operating at 2.3GHz in an urban environment. The analysis includes a comparison of simulated and experimental results. Simulated packet error rate (PER) versus Signal to Noise Ratio (SNR) graphs are generated on a per link-speed basis using a fully compliant 512 carrier mobile WiMAX simulator. Experimental data is gathered using a carrier-class basestation, a mobile-WiMAX enabled laptop, and a suite of application layer logging software. An H264 AVC encoder and IP packetisation unit is used to transmit video to a mobile client. Results show strong agreement in terms of simulated and captured PER. Using this data, the downlink operating range is evaluated as a function of the Effective Isotropic Radiated Power (EIRP) and path loss exponent. Results indicate that at low EIRP (32 dBm) the expected outdoor operating range is around 200-400m. Applying the UK OFCOM regulations for licensed operation in the 2.5GHz band, downlink operation in excess of 2km can be achieved

Indoor Channel Characterization and Performance Analysis of a 60 GHz near Gigabit System for WPAN Applications

ISBN 978-953-7619-X-

In-Building Radio Propagation Characteristics at UHF Frequencies

When both the base station and subscriber antennas are located in the cluttered multipath environment inside buildings, fast fading is observed as either antenna is moved over a distance on the order of a wavelength. The fast fading is evident in measurements made on CW signals, on individual arrivals for pulsed excitation, even for pulses as short as 5 ns. The statistical properties of the fading are discussed, along with the usual measures of the pulse response, such as path loss, mean excess delay, rms delay spread and coherence bandwidth

High-resolution multipath channel parameter estimation using wavelet analysis

This thesis explores the novel use of wavelet analysis as a high-resolution digital signal processing algorithm for multipath channel parameter estimation. The results obtained from this research indicate that this wavelet-based digital signal processing algorithm overcomes the resolution limitation in conventional high-resolution algorithm. This may provide a more cost-effective means of implementing channel sounding equipments for very high-resolution measurements

Review of In-Building Propagation Phenomena at UHF Frequencies

men both the base station and subscriber antennas are located in the cluttered multipath environment inside buildings, fast fading is observed as either antenna is moved over a distance on the order of a wavelength. The fast fading is evident in measurements made on CWsignals, on individual arrivals forpulsed excitation, even forpulses as short as 5 ns. The statistical properties of the fading are discussed, along with the usual measures of the pulse response, such as path loss, mean excess delay, rms delay spread and coherence bandwidth

Indoor off-body wireless MIMO communication with dual polarized textile antennas

Off-body data communication for firefighters and other rescue workers is an important area of development. The communication with a moving person in an indoor environment can be very unreliable due to channel fading. In addition, when considering off-body communication by means of textile antennas, propagation is affected by shadowing caused by the human body. By transmitting and receiving signals using multipleinput, multiple-output antennas (MIMO communication) a large improvement in reliability of the wireless link is obtained. In this contribution, the performance of wireless data communication using quadrature phase shift keyed (QPSK) modulated data in the 2.45 GHz ISM-band is evaluated in the case of firefighters walking indoor and communicating by means of a compact dualpattern dual-polarization diversity textile patch antenna system integrated into their clothing. Simultaneous transmit diversity (at the firefighter) and receive diversity (at the base station) up to fourth order are achieved by means of orthogonal space-time codes, providing a maximum total diversity order of 16. The measurements confirm that MIMO techniques drastically improve the reliability of the wireless link. Measurements are compared for three test persons of significantly different sizes. For equal transmitted power levels, the bit error rates for the 2×2 and 4 × 4 links are much lower than for a system without diversity, with the 4 × 4 system clearly providing the best performance