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M-ary Chirp UWB System using CR Techniques
Hanbing Shen,Weihua Zhang,Kyung Sup Kwak 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7
In this paper, we propose a modified multi-band chirp scheme in the M-ary pulse shape modulation (PSM) UWB system. The initial waveforms for the system are traditional linear chirp waveforms. When the narrowband interference (NBI) is detected, non-linear chirp is adopted in the sub-band where interference exists, the affect of the NBI thus can be reduced in some extend. Therefore, cognitive UWB radio can be realized by the proposed scheme. We discuss the design method of proposed scheme and compare it with the traditional chirp scheme by simulation. The results show that the proposed scheme can outperform the traditional chirp scheme.
Chirp-Based Cognitive Ultra-wideband Radio
Hanbing Shen,곽경섭,Weihua Zhang 한국전자통신연구원 2007 ETRI Journal Vol.29 No.5
In this letter, we propose a cognitive ultrawideband radio scheme which is based on a modified chirp waveform. Therefore, it requires only time domain processing in the cognitive radio systems and reduces system complexity and power consumption.
Non-linear Chirp UWB Ranging System with Narrowband Interference Suppression Abilities
Hanbing Shen,Weihua Zhang,곽경섭 한국전자통신연구원 2007 ETRI Journal Vol.29 No.4
In this letter, we analyze an ultra-wideband ranging system based on non-linear chirp waveforms with the ability of narrowband interference suppression. A number of non-linear chirp waveforms are proposed and evaluated by simulation. The results verify that the proposed schemes can suppress the Narrowband interference to a certain degree.
DS-PAM UWB System Using Non-linear Chirp Waveform
Hanbing Shen,곽경섭,Weihua Zhang,Xizhi An 한국전자통신연구원 2007 ETRI Journal Vol.29 No.3
We propose a direct-sequence pulse-amplitude modulation (DS-PAM) ultra-wideband (UWB) system which employs a non-linear chirp waveform instead of the conventional Gaussian monocycle in this paper. In the approved frequency for UWB, there exist myriad narrowband interferers. Specifically, we focus on the mutual interference between UWB systems and 802.11a WLAN. This paper offers a method to suppress this in-band narrowband interference by introducing a kind of non-linear chirp waveform. Using the proposed non-linear chirp waveform, the effects of one or more narrowband interference sources with different frequencies can be suppressed. System performance of UWB systems in the narrowband interference environment can be improved. Computer simulations with additive white Gaussian noise successfully demonstrate an increase in performance with the proposed system as compared to traditional linear chirp systems.
Impulse Series for UWB-Based Cognitive Radio System
Weihua Zhang,Hanbing Shen,Zhiquan Bai,곽경섭 한국전자통신연구원 2007 ETRI Journal Vol.29 No.4
In this letter, we propose an impulse series for an ultra-wideband-based cognitive radio system which can utilize the spectrum dynamically by controlling the impulse positions and thus reduce the system complexity.