Yoshitaka Hara

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This paper compares multi-carrier code division multiple access (MC-CDMA) with cyclically prefixed direct sequence CP-DS-CDMA in an uplink channel. For the CP-DSCDMA scheme, we propose an MMSE-based multi-user detection (MUD) technique, which recovers code orthogonality among users destroyed by frequency-selective fading in the frequency domain. On the(More)
It is well known that orthogonal frequency-division multiplexing (OFDM) is robust to frequency-selective fading in wireless channels due to the exploitation of a guard interval that is inserted at the beginning of each OFDM symbol. However, once delayed signals beyond the guard interval are introduced in a channel with a large delay spread, intersymbol(More)
This paper proposes a novel downlink spatial scheduling algorithm in multiuser MIMO systems, which selects good combination of terminals and base station(BS)’s transmit beams so that the BS’s beams nullify inter-stream interference at the selected terminals. In the derivation process, we reveal new property that the optimization problem of downlink spatial(More)
AbsfracrThis paper proposes a new Maximum Likelihood OFDM receiver for multipath fading environment with large delay spread The large delay difference over the Guard Interval (GI) duration of the OFDM signal generally results in Inter-Symbol Interference (ISI) between temporally adjacent symbols and Inter-Channel Interference (ICI). Both of them spread over(More)
We propose a method to recognize cups on desks and to detect liquids in cups with a depth camera using triangulation. When we measure an opaque liquid in a cup with the depth camera, the liquid surface is measured. On the other hand, when we measure a transparent liquid, the raised bottom is measured due to the principle of light refraction and(More)
Promising results have been reported with blood purification as adjuvant treatment; however, the immunological mechanisms remain unclear. We have been developing a new blood purification system for regulating excessive immune reactions in severe sepsis and septic shock using a granulocyte adsorbing column (Adacolumn [Ada]), and a cytokine-adsorbing(More)
The high mobility group box 1 protein (HMGB1) is an alarmin that plays an important role in sepsis and has been recognized as a promising target with a wide therapeutic window; however, no drugs and devices are currently in practical use. We hypothesized that hemofilters composed of porous membranes or cytokine-adsorbing membranes could remove HMGB1 from(More)
This paper proposes a new antenna array calibration using frequency selection in OFDMA/TDD systems. In the proposed method, subbands or frequencies of good channel conditions are initially selected for accurate channel measurement. Next, the relative calibration is performed at the selected subbands, in which mismatch of analog gains in multiple antennas is(More)
This paper proposes a novel pre-FFT type OFDM adaptive array antenna called “Eigenvector Combining.” The eigenvector combining is a realization of a post-FFT type OFDM adaptive array antenna through a pre-FFT signal processing, so it can achieve excellent performance with less computational complexity and shorter training symbols. Numerical results(More)