Transmission capacity of ad hoc networks with spatial diversity

Abstract

This paper derives the outage probability and transmission capacity of ad hoc wireless networks with nodes employing multiple antenna diversity techniques, for a general class of signal distributions. This analysis allows system performance to be quantified for fading or non-fading environments. The transmission capacity is given for interference-limited uniformly random networks on the entire plane with path loss exponent α > 2 in which nodes use: (1) static beamforming through M sectorized antennas, for which the increase in transmission capacity is shown to be Θ(M 2 ) if the antennas are without sidelobes, but less in the event of a nonzero sidelobe level; (2) dynamic eigen-beamforming (maximal ratio transmission/combining), in which the increase is shown to be Θ(M 2 α ); (3) various transmit antenna selection and receive antenna selection combining schemes, which give appreciable but rapidly diminishing gains; and (4) orthogonal space-time block coding, for which there is only a small gain due to channel hardening, equivalent to Nakagami-m fading for increasing m. It is concluded that in ad hoc networks, static and dynamic beamforming perform best, selection combining performs well but with rapidly diminishing returns with added antennas, and that space-time block coding offers only marginal gains.

Impact of the Secondary Network on the Outage Performance of the Primary Service in Spectrum Sharing

“…Parameter α > 2 is the pathloss exponent. It most be noted that for x = y, l(x, y) → ∞; however, since similar to [14], our main focus in this paper is to evaluate the probabilistic behavior of the network, this singularity does not have major effect on the obtained results.…”

The performance of successive interference cancellation in random wireless networks

“…In an interference-limited network, a particular user at x ∈ Φ can be successfully decoded (without SIC) iff where h x x −α is the received signal power from x, y∈Φ\{x} h y y −α is the aggregate interference from the other active transmitters, and θ is the SIR decoding threshold 3 .…”

On Two-Tier Femtocell over Fading Environments

“…Generally, small coverage size of a femtocell is considered since the tier of femtocell is installed in indoor application. Based on such assumption, the variance of , F F I is able to be written as [12]  …”

“…The investigation in CR (cognitive radio) with the schemes of sensing-throughput tradeoff for computing optimal sensing time by CR users and limit transmit power of CR users are presented in [9] and [10,11], respectively. The analysis of channel capacities in an ad hoc network with spatial diversity is illustrated in [12]. Though the factor has been proof that nearly 25 multiplies improvement in overall spatial reuse and has been proposed in related researches in [12], in which the assumption is moving from a marcocell-only network to a two-tier underlay with 50 femtocells per cell-site with the OP (outage probability) criteria.…”

“…The analysis of channel capacities in an ad hoc network with spatial diversity is illustrated in [12]. Though the factor has been proof that nearly 25 multiplies improvement in overall spatial reuse and has been proposed in related researches in [12], in which the assumption is moving from a marcocell-only network to a two-tier underlay with 50 femtocells per cell-site with the OP (outage probability) criteria. The research of system performance for time-hopping MC-CDMA (multi-carrier coded-division multiple-access) system has been reported in [13], however, it didn't include the discussion of two-tier femtocell environments.…”