This paper presents an interference suppression and signal restoration technique that can create the clean signals required by automotive frequency-modulated continuous wave radar systems. When a radar signal from another radar system interferes with own transmitted radar signal, the target detection performance is degraded. This is because the beat frequency corresponding to the target cannot be estimated owing to the increase in the noise floor. In this case, advanced weighted-envelope normalization or wavelet denoising can be used to mitigate the effect of the interference; however, these methods can also lead to the loss of the desired signal containing the range and velocity information of the target. Therefore, we propose a method based on an autoregressive model to restore a signal damaged by mutual interference. The method uses signals that are not influenced by the interference to restore the signal. In experiments conducted using two different automotive radar systems, our proposed method is demonstrated to effectively suppress the interference and restore the desired signal. As a result, the noise floor resulting from the mutual interference was lowered and the beat frequency corresponding to the desired target was accurately estimated.

We have fabricated the transparent bottom gate and top gate TFTs using new oxide material of Al-Zn-Sn-O (AZTO) as an active layer. The AZTO active layer was deposited by RF magnetron sputtering at room temperature. Our novel TFT showed good TFT performance without post-annealing. The field effect mobility and the sub-threshold swing were improved by the post-annealing, and the mobility increased with SnO2 content. The AZTO TFT (about 4 mol% AlOx, 66 mol% ZnO, and 30 mol% SnO2) exhibited a mobility of 10.3 cm2/Vs, a turn-on voltage of 0.4 V, a sub-threshold swing of 0.6 V/dec, and an on/off ratio of 109. Though the bottom gate AZTO TFT showed good electrical performance, the bias stability was relatively poor. The bias stability was significantly improved in the top gate AZTO TFT. We have successfully fabricated the transparent AMOLED panel using the back-plane composed with top gate AZTO TFT array.

The uplink performance of WCDMA with voice and World Wide Web (WWW) traffic over Dedicated Channel (DCH)/Common Packet Channel (CPCH) is investigated. The probability of voice packet dropping and average data packet delay are obtained by system level simulation. The system level simulation is conducted based on received Signal-to-Interference Ratio (SIR) with imperfect power control. In addition, we show that the performance of CPCH in terms of probability of data packet dropping is superior to that of DCH for transmitting WWW traffic. Furthermore, we obtain the supportable number of voice users when the target probability of voice packet dropping is set to be 10-2. The supportable number of data users is also found around knee area of average data packet delay.

New service concepts involving mobile devices with a diverse range of embedded sensors are emerging that share contexts supporting communication on a wireless network infrastructure. To promote these services in mobile devices, we propose a method that can efficiently detect a context provider by partitioning the location, time, speed, and discovery sensitivities.

In fast frequency hopped (FFH) non-coherent MFSK systems, the diversity combining scheme can be used effectively in order to combat the interference, especially jamming noise. In this paper, we simulate and discuss the BER performance of FH/MFSK system for different diversity combining schemes, such as linear combining, clipped-linear combining, normalized envelop detection (NED), order statistics (OS) NED and product combining receiver (PCR), in the presence of both the worst case partial band jamming (PBJ) and the fading channel. The performances of those combining schemes except for linear combining are similar each other in the worst case PBJ without the fading. In the existence of both the worst case PBJ and the fading channel, the clipped-linear combining scheme suffers a larger drop in performance than other combining schemes. It is noteworthy that the performances of OSNED and PCR are the best in Rayleigh fading channel among those combining schemes.

In order to investigate the sensitivity of fast frequency hopping-multiple access (FFH-MA) systems due to the frequency offset under Rician fading, we evaluate the bit error rate (BER) performance of the FFH-MA system using noncoherent M-ary frequency shift keying (FSK) with the hard decision decoding and the majority logic decision. Numerical results show that for satisfying the BER performance of 10-5 at a given normalized frequency offset of 0.2, the additional signal to noise ratio (SNR) of about 4 dB is required with the 8-ary FSK signaling compared to the case of the perfect frequency synchronization. While the frequency offset increases at a given SNR, the BER is more severely degraded, and subsequently, the BER performance is saturated at the normalized frequency offset of 0.5 regardless of fading environments. For the SNRs of more than 15 dB, the threshold level of the receiver suffering from normalized frequency offsets of less than 0.4 should be larger than that of the perfectly frequency synchronized receiver.

Satellite communication can be operated with various levels of on-board processing in order to transmit the signal effectively. In this paper, the BER performances of the bent pipe transponder (BPT), dehop only transponder (DOT) and dehop and rehop transponder (DRT) systems with FH-MFSK modulation are investigated in the presence of broad band interference, narrow band interference and tone-type interference. In this case, the BER performances are compared for the variants of the data rates, spreading bandwidth and interference power. The numerical results show that DRT outperforms BPT and DOT. DOT is less sensitive to uplink interference power under broad band interference environment than DRT. In the case of narrow band interference, the DRT system is more sensitive to ρ value, i.e., the ratio of the interference bandwidth to the spreading bandwidth, than DOT. Among various interference types, the performance in n = 1 band multi-tone interference is shown to be the worst.

The bit error rate (BER) performance of a fast frequency-hopped frequency division multiple access (FH-FDMA) system is evaluated with diversity combining receivers. The clipper receiver and the normalized envelope detection (NED) receiver which show better performance than other diversity combining receivers under n = 1 band multitone interference (MTI) are chosen as combining alternatives. From simulation results, n = 1 band MTI is the most destructive multitone interference strategy for the FH-FDMA system. As the number of groups increases, eventually becoming a FHMA system, the worst case performance of FH-FDMA with the clipper receiver improves monotonically, while that of the NED receiver hardly improves when the effect of the interference is relatively large. From the viewpoint of BER performance, the FHMA system with the clipper receiver is the most effective solution among the FH-FDMA systems in the presence of the worst case band MTI.

A 1T2C-type ferroelectric memory cell, in which two ferroelectric capacitors with the same area are connected to the gate of an usual MOSFET with a SiO2/Si interface, was fabricated and characterized. The relations between various device parameters and characteristics of memory cell were investigated by using SPICE simulation. It was found from the simulation results that the memory window significantly changed by the device parameters, which means that the operation voltage of the memory cell can be well controlled by these parameters. The fabricated cell is composed of a stacked gate structure of Pt/SBT/Pt/Ti/SiO2/Si with the area ratio of the MOS capacitor (SO) to the ferroelectric capacitor (SF) of 6 or 10. Nonvolatile memory operation was confirmed, and the obtained memory window coincided with the simulated results qualitatively. Furthermore, the current on/off ratio in the read-out operation was larger than 3-order-of magnitude and the data retention time was longer than 6 104 seconds. It was also predicted that low voltage operation was possible if the device parameters were optimized.

The stage 3/2 decoding scheme, originally suggested by U. Timor, is modified for a Rayleigh fading channel to improve the performance of a fast frequency-hopped multiple access/multilevel frequency shift keying system. When signal-to-noise ratio per bit is 30 dB, the simulation results show that the modified stage 3/2 decoding scheme increases the spectral efficiency by 11% compared to the modified stage 1 decoding scheme at bit error rate of 10-3. Further, the performance comparisons are made between the modified multistage decoding scheme and the diversity combining methods, where the modified stage 3/2 decoding scheme shows better performance.

Support vector algorithms try to maximize the shortest distance between sample points and discrimination hyperplane. This paper suggests the total margin algorithms which consider the distance between all data points and the separating hyperplane. The method extends and modifies the existing algorithms. Experimental studies show that the total margin algorithms provide good performance comparing with the existing support vector algorithms.