Wideband Sounder for Dynamic and Static Wireless Channel Characterisation: Urban Picocell Channel Model

Abstract

Abstract-This paper presents a high speed configurable FPGAbased wideband channel sounder with signal bandwidths up to 200 MHz and results of a study of dynamic urban picocell channel. The use of FPGA allows the sounder to be adaptable for measurements in different scenarios. Adaptable options include changes to the waveform, bandwidth, channel sampling rate and real-time averaging to improve signal-to-noise ratio in weak signal conditions. The implemented architecture has led to a 60% reduction in size and weight compared to sounders in use elsewhere making it ideal for mobile channel measurements. The study of an urban picocell channel has shown that dynamic variation due to automotive traffic introduces average signal fades of up to 5 dB but causes frequency selective fading with depths of up to 40 dB. Existing channel models assume antenna heights of more than 6 m and path lengths of more than 30 m. Therefore there is a need for shorter path models and this paper proposes a linear picocell channel model for static and dynamic urban environment.

Signal Propagation Analysis for Low Data Rate Wireless Sensor Network Applications in Sport Grounds and on Roads

“…The focus of most studies has been on the system architecture [31] and little attention has been paid to wireless signal propagation issues. Research reported in [33] showed that vehicles induce signal fades that are up to 40 dB, even when they do not traverse the transmitter to receiver path.…”

Measurement Evaluation of the TGN Radio Channel Models Usefulness in Predicting Wlan Performance

“…Thus, the signal arriving at the receiver will not come in a single fringe, but as a pack of signals with different amplitudes, phases, angles of arrival, and short time delays, being delayed copies of the original signal [7][8][9][10][11][12][13][14][15][16]. Once collected within a certain time span at a receiver, they sum up in a vector fashion, accounting for their relative phase differences, which causes some copies to overlap constructively if both are in phase or cancel out otherwise.…”

“…The complex Additive White Gaussian Noise (AWGN), given by Equation (12), was also added to the signal, with a n (t) and b n (t) components being independent real Gaussian variables with zero mean and a standard deviation σ n . The average noise power P n of the AWGN can be found from Equation (13).…”

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“…Thus, the signal arriving at the receiver will not come in a single fringe, but as a pack of signals with different amplitudes, phases, angles of arrival, and short time delays, being delayed copies of the original signal ( [5,6,9]). Once collected within a certain time span at a receiver, they sum up in a vector fashion, accounting for their relative phase differences, which causes some copies to overlap constructively if both are in phase or cancel out otherwise.…”

“…The mean excess delay τ m is the first moment of the power delay profile and is defined by Equation (5) and has the sense of the first moment of the PDP. Finally, τ rms , having the sense of the second central moment of the PDP, see Equation (6), is a measure of the channel time dispersiveness and determines the maximum symbol rate achievable by a communication system before inter-symbol interference (ISI) occurs (see also [7,8] for details).…”