This paper proposes novel channel estimation weights for multiple differential detection based on per-survivor processing (PSP-MDD). Channel estimation weights for PSP-MDD can control a trade-off between performance in the required signal-to-noise power ratio (SNR) and tracking capability. There have been proposed the two channel estimation weights: weights of simple first-order channel prediction and weights of higher-order channel prediction based on the binomial theorem. In order to control this trade-off widely and precisely, this paper proposes channel estimation weights generalizing the two conventional weights. Finally, computer simulation results confirm that the proposed weights can control the trade-off widely and precisely.
We describe dynamic channel properties based on diffuse scattering from vehicles for high frequency bands in a non-line-of-sight (NLOS) urban environment. We investigate the dominant paths based on the measured power delay angular profile in experiments using a 20-GHz band channel sounder. Based on the results, we clarify that arrival waves from buildings and diffuse scattering from vehicles represent dominant paths in NLOS urban environments. Also, we find that the fading of scattering paths from vehicles is approximately 26 dB in those paths between birth and death.
PageRank is widely known as a prominent method used for indexing web pages and has significantly contributed to the development of Google’s search engine. Significant contributions have been made to the analyses of PageRank, in particular, its sensitivity analyses. However, the arguments presented thus far are within in the range of the matrix perturbation theory or the analyses of Markov chains. This paper explores the application of Kato’s perturbation theory to study the sensitivity analyses of PageRank, which enables the consideration of a larger number of general situations than those in established arguments.