Earticle

This paper proposes an efficient full-duplex multiple input multiple output (MIMO) relay in wireless multihop networks. The proposed relay consists of a minimum mean square error (MMSE) filter, a decode-and-forward protocol processor, and a modified Alamouti encoder. In consideration of the tradeoff between performance and complexity, the MMSE filtering is presented to suppress the spatial loop interference, and the modified Alamouti encoding is simply added to improve the performance of the destination by intimately collaborating with the relay. Simulation results confirm that the proposed method outperforms the conventional methods at the expense of a reasonable increase in complexity.

In this paper, the break-lock phenomenon of phase locked loop (PLL) in monopulse radar receiver for missile seeking applications is presented. The continuous wave radar echo and linear frequency modulated (LFM) interference signals are injected into the PLL simultaneously with an assumption that initially, the PLL locks on to the echo signal frequency. The PLL is assumed to be operating at an intermediate frequency (IF) of 50 MHz with a typical bandwidth of 200 kHz. The frequency deviation required to break-lock as a function of interference signal power and modulation rate is analyzed. The simulation results show that break-lock is achieved at a frequency deviation of 0.36 MHz for a typical LFM signal power of -14 dBm and 200 kHz modulation rate. The break-lock in the PLL is also estimated for selected values of LFM signal power and modulation rates, such as 300, 400 kHz, when the echo signal power at the PLL input is -10 and -14 dBm. The PLL with third order passive loop filter is modeled and designed using exact method. The computer simulation is carried out using visual system simulator (VSS) AWR software and potential conclusions are demonstrated.

본 논문에서는 무선가입자망과 무선LAN과의 가드 밴드 문제를 지적하였고, 무선가입자망의 기술들을 살펴보았으며, 무선가입자망과 무선LAN과의 전파간섭을 분석하였다. 본 논문의 내용들은 무선가입자망 설비의 기술적 조건을 제정하는데 도움이 될 것이다.

In this paper, we point out the problem of guard band between wireless local loop and wireless LAN, review technologies of wireless local loop, and analyze radio interference between wireless local loop and wireless LAN. The contents of this paper are helpful to make a rule for technical specifications of wireless local loop facilities.

본 논문에서는 PDL 기반 인터리빙 가능한 2차 Solc형 광유 간섭 필터를 제안하며, 출력되는 투과 스펙트럼들을 이론적으로 분석 및 실험적으로 측정하였다. 제안된 필터에서 각각의 구성요소는 편광 빔분배기, 반파장판, 그리고 복굴절이 큰 광섬유로 이루어진다. 이전의 Solc형 2차 광섬유 필터에서 복굴절이 큰 광섬유들은 특정한 각도로 융착 결합되어 편광 제어에 한계가 있었지만, 제안된 구조에서는 복굴절이 큰 광섬유 사이 반파장판을 삽입하여 주축의 각도 및 편광 제어를 유연하게 설정하여 출력 투과 스펙트럼들의 스위칭 특성을 유도하였다.