Integration time of the correlation receiver for a Nyquist optical time-division multiplexing (OTDM) scheme is limited by the multiplicity of the OTDM scheme. We investigate the signal degradation caused by the finite integration time of the correlation receiver. The signal degradation factor is analyzed by separating it into noise resistance degradation and inter-symbol interference. We also conduct numerical simulations to estimate the required multiplicity number and roll-off factor for suppressing the signal degradation.
We numerically analyze the heating characteristics of a realistic anatomical model of human body using multi-electrode method in the radio-wave hyperthermia of tumors. It is clarified that we can suppress heating around the electrode and achieve higher heating of tumor as compared to the conventional method.
We propose a novel multi-level pre-equalizer composed of multiple binary analog finite impulse response (FIR) filters. The performance was investigated using numerical simulation of a 20-Gb/s four-level pulse-amplitude-modulation (4-PAM) multi-mode fiber (MMF) transmission system. The analog FIR filters were designed using 28 nm fully depleted silicon on insulator (FD-SOI) based complementary metal-oxide-semiconductor (CMOS) circuits. The simulated CMOS circuits successfully compensated the multi-level signals distorted by modal dispersion. The error vector magnitude (EVM) of the transmitted 4-PAM signals was improved from 40% to 9%. The proposed design scheme will enable cost-effective, low-power analog FIR filters for multi-level pre-equalization.
This paper presents theoretical analysis and empirical evaluation of noise factor of active-tile two-dimensional communication (2DC) system. 2DC uses a thin waveguide sheet for microwave propagation along the sheet. For implementing a room-scale 2DC, an active tile, which compensates signal loss with an active circuit and enables signal propagation across a number of sheets, has been proposed in our previous work. Although the signal strength is kept constant across the tiles, signal-to-noise ratio (SNR) decreases due to the noise factor of amplifiers. It determines the maximum number of 2DC tiles connected in series while providing a required SNR. The paper shows SNR formulation using the noise factor of each active tile and the number of tiles in a series connection. Based on it, the maximum number of tiles connected in series with a required overall SNR is determined.
This paper describes the performance evaluation of a state-of-the-art adaptive control cell range expansion (CRE) technique in Heterogeneous Network (HetNet) with enhanced inter-cell interference coordination (eICIC) scheme. The features of the proposed adaptive control CRE technique are described through comparison with those of conventional methods. System-level computer simulation results such as average and 5-percentile user throughput are provided under the conditions of HetNet with eICIC, as parameters of almost blank subframe (ABS) ratio for eICIC. We confirmed that the proposed adaptive control CRE can improve 5-percentile user throughput while maintaining the average user throughput even for HetNet with eICIC.
We numerically analyze the specific absorption rate (SAR) in the eye of anatomically based human whole-body model exposed to E-polarized plane wave in the frequency range from 0.6 to 4 GHz. As a result, we find a clear resonance that the average SAR is about 57% larger at the maximum than that of the isolated head.
The authors have proposed the signal decomposition technique as the powerful solution to mitigate the large peak-to-average power ratio (PAPR) to be addressed in OFDM transmitters, and the simple noise elimination techniques working together with the signal decomposition in receivers. It is shown that the proposed signal decomposition technique improves the PAPR by 4 dB and doubles the power added efficiency (PAE) at the complementary cumulative distribution function (CCDF) of 1%. In order to show the feasibility of the proposed techniques when they are applied to MIMO transmissions, BER performances of the proposed techniques are also demonstrated.