Large-Scale Site and Frequency Diversity in Urban Peer-to-Peer Channels for Six Public-Safety Frequency Bands

Abstract

Abstract-We report on peer-to-peer large-scale wireless channel characteristics for an urban environment in six public-safety bands, for five simultaneous receiving sites. Results are based upon measurements taken in Denver in July 2009 with stationary receivers and a pedestrian transmitter. The six frequencies at which we measured are (in MHz) 430, 750, 905, 1834, 2400, and 4860. We quantify both site and frequency diversity, and show that 5-site selection yields minimum average gains of 15 dB in mean received power levels; 5-site selection diversity also reduces received power variation by 17-29 dB, depending on frequency. Frequency diversity yields similar gains. By approximating received powers as lognormal, we describe an analytical method to approximate the cdf of the per-site, or per-frequency (or both) maximum received power. These data and diversity models should be useful for public-safety and ad hoc communication system designers, and for cooperative diversity schemes, wherein multiple users act as a virtual array.

Capacity Analysis of Hybrid Satellite–Terrestrial Systems with Selection Relaying

“…Due to the relatively small diameter of the beam (L << H), it can be assumed that the elevation angles at both the destination and relay satisfy the condition θ R = θ D = θ, and the corresponding distances and path loss factors are approximately the same, i.e., d SD ≈ d SR , n SD ≈ n SR , and therefore γ = γ i , i = 1, 2. The terrestrial link operates in the urban environment, with a higher path loss factor, where n RD = 4 [52]. If it is not differently stated, we also assume that the P R is adjusted to provide approximately the same average SNR in all channels (i.e., γ i = γ, i = 1, 2, 3), and, for the parameters presented in Table 2, we obtain that γ = 13.2 dB.…”