Masanori Hamamura

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SUMMARY We propose a novel asynchronous direct-sequence code-division multiple access (DS-CDMA) using feedback-controlled spreading sequences (FCSSs) (FCSS/DS-CDMA). At the receiver of FCSS/DS-CDMA, the code-orthogonalizing filter (COF) produces a spreading sequence , and the receiver returns the spreading sequence to the transmitter. Then the transmitter(More)
In this paper, we present the results of analysis, which shows that there is much to be gained from variable frame length, different modulations in terms of goodput, range and energy consumption for wireless channel. Using those results, then we obtain three useful rules for the tradeoff with goodput, range and energy consumption with different modulations
SUMMARY We propose multitone-hopping code-division multiple access (MH-CDMA) using a feedback-controlled hopping pattern (FCHP) (FCHP/MH-CDMA). In the FCHP/MH-CDMA, part of the filter coefficients of an adaptive finite-duration impulse response (FIR) filter receiver are fed back to a transmitter, in which they are used as an updated hopping pattern. Each(More)
This paper presents BER performance of several FH/M-ary multilevel FSK (abbr.MMFSK) and OFDM (MC-SS type) systems using limiters, and compares their properties in an AWGN channel and in a high frequency power-line. The proposed MMFSK systems are modified by using a parallel system and a multi-tone combination system. As a limiter, a soft clipper is adopted.(More)
We propose a smooth approximation l(0)-norm constrained affine projection algorithm (SL0-APA) to improve the convergence speed and the steady-state error of affine projection algorithm (APA) for sparse channel estimation. The proposed algorithm ensures improved performance in terms of the convergence speed and the steady-state error via the combination of a(More)
SUMMARY In this paper, we propose a new modulation named parallel combinatory/high compaction multi-carrier modulation (PC/HC-MCM) using the techniques of parallel combinatory orthogonal frequency division multiplexing (PC-OFDM) and high compaction multi-carrier modulation (HC-MCM). Two types of PC/HC-MCM systems, which are named as modulated PC/HC-MCM(More)
To make use of the sparsity property of broadband multipath wireless communication channels, we mathematically propose an l p -norm-constrained proportionate normalized least-mean-square (LP-PNLMS) sparse channel estimation algorithm. A general l p -norm is weighted by the gain matrix and is incorporated into the cost function of the proportionate(More)