This letter derives the theoretical BER of coded SC-FDE transmission taking advantage of the traditional theoretical results of the instantaneous SINR. The proposed approach is inspired by the fact that the theoretical channel coding gain under AWGN is directly applicable to the traditional FDE performance due to the flat SINR characteristic within an FDE block. The proposed derivation method can provides the theoretical coded BER without any effort of actual signal processing such as modulation, demodulation, and channel coding. The validity of the proposed approach is confirmed by the agreement with the computer simulation results under frequency selective fading channels.

A mechanical linear sliding phase shifter using waffle-iron ridge guides (WRG) and its application to a beam steering antenna are shown. The structure of the new phase shifter is simpler than we have presented previously in that the number of metal layers has been reduced. Another advantage of the new phase shifter is that with it simple beam steering antennas can be realized. This paper explains the principle and the characteristics of the phase shifter and gives an example of a beam steering antenna.

We investigate the effect of the cut-off frequency and number of quantization bits of analog-to-digital converters on the signal quality in a Nyquist optical-time-division-multiplexing scheme using the impulse response of a correlation receiver. The cut-off frequency and number of quantization bits required at a baud rate of 160 GBd are determined through numerical simulations.

We propose an interstitial coaxial antenna that can insert without a catheter for microwave ablation therapy, operating at 2.45 GHz. The cap of the antenna is an arrowhead that bonds copper plate and ceramic plate to suppress heat conduction in the tip direction. The temperature distribution in the improved liver phantom is measured by using the infrared thermography device. As a result, it is clarified that we nearly get the spherical distribution of an assumed tumor in shape.

We propose a novel two-tone signal generation method using a dual-parallel Mach-Zehnder modulator (DP-MZM). One MZM in the DP-MZM is used to generate a basic two-tone signal with high-order harmonics, which cause waveform distortion. The other MZM is used to compensate third-order harmonics, which are the most dominant cause of distortion. The proposed method was investigated by numerical simulation and experiment. In the experimental demonstration, suppression of the third-order harmonics component was improved by 20 dB.

In this letter, we consider the information theoretically secure key agreement where the legitimate users have a virtual eavesdropper to estimate the statistics of wiretapping. We propose a computational procedure which can estimate the virtual eavesdropper’s conditional entropy even with the finite number of pilot pulses and without restricting any probatility family for the wiretap channel.

This letter studies a pilot sharing scheme for spectrum-sharing massive MIMO networks, where primary network (PN) can lease portion of orthogonal pilots to secondary network (SN) for channel estimation. We assume that PN and SN are rational and selfish, and they aim at maximizing their revenue when pilots are traded. Then, we propose a price-based iterative optimal pilot allocation algorithm to obtain win-win paradigm, while guaranteeing the primary user ratio (PUR) of the primary cell. Simulation results reveal that PN can achieve more revenue by sacrificing limited pilots while decreasing total interference to adjacent cells.

Super-resolution time of arrival estimation methods have attracted much attention in radar signal processing. Many studies have used compressed sensing (CS)-based approaches to attain the super-resolution property because they assume sparseness of temporal distribution of target signal. However, this approach still suffer from accuracy degradation when decomposing highly correlated signals in heavily noise-contaminated situations. To resolve this problem, this study introduces an enhanced CS method by exploiting the sparseness of the signals in terms of both time and frequency domains. Numerical simulation and comparison with results obtained by conventional methods demonstrate that the proposed method considerably enhances the reconstruction accuracy for multiple highly correlated signals in lower signal-to-noise ratio situations.

This paper presents the performance evaluation for secondary networks with multiple primary users (PU) with a stochastic geometry approach. On the assumption that the secondary users (SUs) follow a Poisson hole process, we derive a PU’s outage probability (OP) and SU’s area spectral efficiency (ASE), where the PU’s OP and SU’s ASE are defined as the probability that the aggregate interference at a PU from transmitting SUs exceeds a threshold and the product of the transmitting SU’s density and the SU’s average throughput, respectively. The theoretical results agree with the simulation results, and these results show that both the PU’s OP and SU’s ASE decrease along with the primary exclusive region (PER) size, i.e., we quantitatively evaluate the trade-off between the PU’s OP and SU’s ASE.

This letter is devoted to a circularly polarized (CP) low-profile antenna radiating parallel to its ground plane. The proposed antenna has a capacitive feeding structure resulting in a small dimension of 0.127λ₀ × 0.059λ₀ and the short height of 0.01λ₀ at 1.77 GHz, where λ₀ is the wavelength at the resonant frequency. Even though the structure is low-profile, the radiation efficiency can reach at 70% (Simulated) with a small gap. The proposed antenna can radiate LHCP (Left-hand CP) and RHCP (Right-hand CP) in the opposite directions parallel to the ground plane.

This paper presents a high-speed radio-resource scheduler that accelerates the scheduling process of fifth-generation mobile communications systems (5G). A scheduler for 5G systems will have to decide the optimal combination of an antenna and user equipment for efficient communications from a huge number of possible combinations. The reported scheduler with a hardware accelerator performs several high-speed searches to find the optimal combination. Experimental results show that it executes several search methods 40 times faster than a scheduler without acceleration. It improves the system throughput and will enable a practical 5G system to be developed.

In this paper, a capacitive coupling Low Temperature Co-fired Ceramics (LTCC) chip antenna is designed and fabricated for Wideband Code Division Multiple Access (W-CDMA) mobile handsets applications. The proposed antenna is designed by utilizing the capacitive coupling structure and feeding by a microstrip line. The proposed antenna has the advantage of good gain and easy to impedance matching. The size of the proposed antenna is 3 × 10 × 0.94 mm³. Gain difference by microstrip-fed and CPW-fed is also discussed and comparative results are simulated and demonstrated. Measured results show that the impedance bandwidth for |S₁₁| less than −10 dB covers two bands of W-CDMA, and the omni-directional radiation pattern is realized.