Abstract-Space shift keying (SSK) modulation and its extension, the generalized SSK (GSSK), present an attractive framework for the emerging large-scale MIMO systems in reducing hardware costs. In SSK, the maximum likelihood (ML) detector incurs considerable computational complexities. We propose a compressed sensing based detector, NCS, by formulating the SSK-type detection criterion as a convex optimization problem. The proposed NCS requires only O(ntNrNt) complexity, outperforming the O(NrN nt t ) complexity in the ML detector, at the cost of slight fidelity degradation. Simulations are conducted to substantiate the analytical derivation and the detection accuracy.

The aim of this study was to investigate the acute effect of (a) a drop jump (DJ) protocol with 1 set per 5 repetitions and (b) a DJ protocol with 2 sets per 5 repetitions on countermovement jump (CMJ) height performance in volleyball players at recovery times of (a) 2 minutes, (b) 6 minutes, and (c) 12 minutes. The subjects were 10 male Division I college volleyball players. They were instructed to perform a pretest of 3 CMJs and then randomly assigned to perform (a) a DJ protocol with 1 set per 5 repetitions and (b) a DJ protocol with 2 sets per 5 repetitions. After the DJ, 3 CMJs were completed in 2, 6, and 12 minutes. A 2-way repeated-measures analysis of variance was used to examine the differences between training volumes and recovery times in CMJ height (H(CMJ)) and maximum ground reaction force. Both DJ training volumes significantly increased the H(CMJ). The H(CMJ) at post 2 minutes was greater than those at the pretest (p = 0.008), post 6 minutes (p = 0.004), and post 12 minutes (p = 0.002). In addition, the H(CMJ) at post 6 minutes was significantly greater than that at post 12 minutes (p = 0.018). Drop jumps in lower volume (e.g., within 10 repetitions) and short recovery time (e.g., within 2 minutes) can produce a positive acute effect on CMJ performance.

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Abstract. We investigate the special fibers of Siegel modular varieties with Iwahori level structure. On these spaces, we have the Newton stratification, and the Kottwitz-Rapoport stratification; one would like to understand how these stratifications are related to each other. We give a simple description of all KR strata which are entirely contained in the supersingular locus as disjoint unions of Deligne-Lusztig varieties. We also give an explicit numerical description of the KR stratification in terms of abelian varieties.