Effective wavelets to solve electromagnetic integral equations are proposed. It is based on the same construction procedure as Daubechies wavelets but with mix-phase to obtain maximum sparsity of moment matrix. These new wavelets are proved to have excellent performance in non-zero elements reduction in comparison with minimum-phase wavelet transform (WT). If further sparsity is concerned, wavelet packet (WP) transform can be applied but increases the computational complexity. In some cases, the capability of non-zero elements reduction by this new wavelets even better than WP with minimum-phase wavelets and with less computational efforts. Numerical experiments demonstrate the validity and effectiveness of the new wavelets.

Mechanism of UHF radiowave propagation into multistory office buildings are explored by using ray-tracing based models, which include a three-dimensional (3-D) ray-tracing model and a direct-transmitted ray (DTR) model. Prediction accuracy of the models is ascertained by many measured data and the measurements are carried out at many specific sites with different propagation scenarios. Their measured results also demonstrate some important propagation phenomena. It is found that (1) the direct transmitted wave may be the dominant mode; (2) the path loss neither increases nor decreases monotonically as a function of increasing floor level; and (3) there is not much difference of the average path loss among the receiving positions in the same room.

The Rician factor is an important parameter in evaluating the outage probability and reuse distance of cellular systems. From the measurement of 1. 8 GHz radio propagation in outdoor urban microcells, it is found that the measured pdf of the Rician factor for low tier systems follows a lognormal distribution and the factor is independent on the propagation distance.

The dynamics of Mobile Ad-hoc NETworks (MANETs), as a consequence of mobility of mobile hosts, pose a problem in finding stable multi-hop routes for communication between a source and a destination. Traditional ad-hoc routing protocols are proposed to find multi-hop routes based on shortest path routing algorithms, which cannot effectively adapt to time-varying radio links and network topologies of MANETs. In this paper, a novel stability-based ad hoc routing protocol, which is named as Ad-hoc On-demand Stability Vector (AOSV) routing protocol, is proposed to properly and effectively discover stable routes with high data throughput and long lifetime by considering the radio propagation effect on signal strength. Here, a stochastic mobile-to-mobile radio propagation model is proposed to predict path loss as well as received signal strength between adjacent nodes, and the estimation of link/route stability is derived from the prediction of signal strength. With awareness of link and route stabilities, a path finding algorithm is designed to explore the stable route with largest route stability for a source and destination pair. The performance of AOSV protocol is compared with the well-known Ad-hoc On-demand Distance Vector (AODV) routing protocol and other related works. Simulation results indicate that the AOSV routing protocol leads to significant throughput increases up to 70% improvement comparing to AODV, and provides better performance than related works.