Abstract
A measurement campaign is introduced for modeling radio channels with either line-of-sight (LoS) or non-line-of-sight (NLoS) connection between user equipment (UE) and NodeB (NB) in an operating universal mobile telecommunications system. A space-alternating generalized expectation-maximization (SAGE) algorithm is applied to estimate the delays and the complex attenuations of multipath components from the obtained channel impulse responses. Based on a novel LoS detection method of multipath parameter estimates, channels are classified into LoS and NLoS categories. Deterministic models which are named “channel maps” and fading statistical models have been constructed for LoS and NLoS, respectively. In addition, statistics of new parameters, such as the distance between the NB and the UE in LoS/NLoS scenarios, the life-distance of LoS channel, the LoS existence probability per location and per NB, the power variation at LoS to NLoS transition and vice versa, and the transition duration, are extracted. These models are applicable for designing and performance evaluation of transmission techniques or systems used by distinguishing the LoS and NLoS channels.
Highlights
Distinctive characteristics of signals coming from a line-ofsight (LoS) or non-line-of-sight (NLoS) path in a wireless environment raised great concerns in mobile radio system design
A channel measurement campaign has been conducted aiming at characterizing LoS/NLoS channels by using the downlink signals in a commercial UMTS network for a pedestrian zone in Nanjing Road, Shanghai
Techniques were developed for extracting the channel impulse responses, and multipath parameters were estimated by using the spacealternating generalized expectation-maximization (SAGE) algorithm
Summary
Distinctive characteristics of signals coming from a line-ofsight (LoS) or non-line-of-sight (NLoS) path in a wireless environment raised great concerns in mobile radio system design. The distributions of the path loss, which can be calculated based on a method that will be introduced later, are applicable to deducing the statistics of the distances between NBs and UE in either LoS or NLoS cases Such information is considered to be useful for channel simulations and designing the transmission power for NBs and UE with respect to the LoS and NLoS scenarios. The observation that ΔPLoS−NLoS is less than 0 dB indicates that, for some transitions, the NLoS scenarios have higher received
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