共查询到17条相似文献,搜索用时 500 毫秒
1.
提出了一种基于FIR陷波器的窄带抑制UWB脉冲设计方法。通过对各种窗函数的陷波性能比较分析,选出最佳的窗函数来设计FIR陷波器。以高斯脉冲导数为例,对所设计陷波器进行仿真验证,并就陷波前后的脉冲波形的通信性能进行了比较。仿真结果表明:陷波后脉冲具有良好的窄带干扰抑制能力,能够和其它通信系统更好地共存。另外,此方法不需要在整个频段内降低UWB脉冲功率,实现起来简单灵活,为提高UWB脉冲发射功率,增大UWB系统的通信距离,提供了一种可行的方案。 相似文献
2.
3.
提出一种基于认知无线电的自适应超宽带窄带干扰抑制方法。基于软频谱思想,利用近似椭球波函数良好的时限-带限特性,设计出一种能够抑制窄带干扰的脉冲波形。通过调整脉冲参数实现对授权频段的动态避让。仿真结果表明:自适应脉冲具有良好的窄带干扰抑制能力,能够自适应地随着感知结果动态地规避授权用户,从而实现UWB系统与其它通信系统的共存。 相似文献
4.
5.
针对卫星导航接收机时域窄带干扰的有效抑制问题,本文首先给出二阶格型IIR陷波器参数设计方法,通过陷波带宽的定量调整,既可以有效抑制窄带干扰,又可以降低卫星信号的失真;其次推导了二阶IIR格型陷波器相关输出信干噪比改善因子的闭合表达式,该表达式相比干扰抑制后信干噪比的改善,更为直观地反映了陷波器对卫星导航信号的影响。理论分析和仿真实验,二阶格型IIR陷波器相关输出信干噪比改善因子与陷波器的带宽参数有关,而与陷波频率无关,且二阶格型IIR陷波器的性能优于最优线性预测Wiener滤波器、最优线性插值Wiener滤波器、五系数FIR滤波器以及二阶直接型IIR陷波器。 相似文献
6.
7.
基于自适应IIR陷波滤波器的窄带干扰抑制技术 总被引:1,自引:0,他引:1
在存在窄带干扰时,扩频通信系统的性能可以通过使用各种不同的抗干扰滤波器来进一步提高。文中研究了二阶自适应格型IIR陷波滤波器在直扩通信中抗窄带干扰的应用,推导了系统信噪比改善因子和误比特率的闭合表达式。计算机仿真表明了该分析结果的正确性。 相似文献
8.
为了滤除窄带信号对超宽带(Ultra-Wide Band, UWB)通信系统的干扰以及解决天线尺寸偏大的问题,设计出一种小型化五陷波UWB天线。该天线通过添加L型枝节、C型槽、倒U型槽以及EBG结构,产生五个陷波带。对天线进行回波损耗(S11)、驻波比(VSWR)以及增益(Gain)等仿真测试,通过天线表面的电流分布情况分析了天线的陷波原理,研究上述结构对天线陷波特性的影响。该天线将UWB通信应用与陷波天线技术相结合,最终尺寸为21 mm×16 mm,实现了体积小、频带宽、多频段陷波特性的性能要求,天线频带覆盖了S、C和X三个波段,具有屏蔽窄带信号干扰的作用,可应用于UWB通信系统。测试结果表明,天线的阻抗带宽为2~12 GHz,在工作频段内具有全向性,并且整个UWB频段内天线的增益变化在4 dB以内,最大增益为4.67 dB,在通带频段内,天线五个陷波特性的结果与仿真结果均吻合良好。 相似文献
9.
10.
研究了直接序列扩频通信系统中幅值相差较大的窄带干扰抑制问题,以一阶复数自适应陷波器为陷波单元,介绍了一种级联结构的陷波器,给出了系数迭代的自适应算法和理论分析。仿真实验表明,该陷波器能有效消除多个窄带干扰,迭代算法具有良好的收敛性能。 相似文献
11.
Narrowband interference suppression in time-hopping impulse radio ultra-wideband communications 总被引:2,自引:0,他引:2
《Communications, IEEE Transactions on》2006,54(6):1057-1067
Ultra-wideband (UWB) technology has been considered an innovative solution for future short-range high-speed wireless communications. Interference suppression is important for the UWB devices to operate over spectrum occupied by narrowband systems. In this paper, the use of a notch filter in time-hopping impulse radio (TH-IR) for UWB communication is considered, where a Gaussian monopulse is employed with pulse position modulation. Lognormal channel fading is assumed, and a complete analytical framework is provided for the performance evaluation of using a transversal-type notch filter to reject narrowband interference (NBI). A closed-form expression of bit-error probability is derived, and the numerical results show that the use of a notch filter can improve the system performance significantly. Furthermore, a performance comparison between TH-IR and multicarrier code-division multiple-access (MC-CDMA) UWB systems is made under the conditions of the same transmit power, the same data rate, and the same bandwidth. It is shown that in the presence of NBI, the TH-IR system and MC-CDMA system achieve similar performance when both use a notch filter. 相似文献
12.
Burak Kelleci Timothy Wayne Fischer Aydın İlker Karşılayan Kai Shi Erchin Serpedin 《Circuits, Systems, and Signal Processing》2008,27(4):475-489
The analysis and optimization of a notch filter to combat in-band narrowband interference (NBI) for multiband orthogonal frequency
division multiplexing (MB-OFDM)-based ultra-wideband (UWB) systems is presented. Unintentional radiation of electronic devices
can reside in the UWB band and jam the communication. Erasing the interference with a programmable analog notch filter reduces
the requirement for the analog-to-digital converter resolution in the presence of NBI. The order and approximation of the
notch filter are determined, and the filter’s bandwidth is optimized to minimize the packet error rate. Simulation results
indicate that the UWB system with suppression scheme can handle up to 14 dB more in-band interference power. 相似文献
13.
在GNSS服务过程中,地面接收到的卫星导航信号的功率较小,且易受到周围复杂电磁干扰影响,这将会导致卫星无法正常定位。针对常见的窄带干扰,介绍一种新型自适应全通IIR陷波器,自适应算法采用高斯-牛顿迭代法,通过跟踪窄带干扰频点,对其频点进行陷波。文中在其基础上进行改进,在每次迭代过程中采用最佳收敛因子,最大程度地减少均方误差。这种算法可导致更快的收敛速度和更高的估计精度。仿真结果表明,IIR滤波器可有效去除高达70 dB的窄带干扰。 相似文献
14.
To suppress narrowband interference (NBI) in an ultra‐wideband (UWB) communications environment, a null phase‐shift polarization (NPSP) filter is proposed. The proposed NPSP filter is a combination of a linear polarization‐vector transformer (PVT), a conventional single notch polarization (SNP) filter, and an amplitude and phase compensator (APC). The NBI, which has polarized states different from those of the UWB, can be suppressed completely and the UWB signal can be recovered without distortion if the polarized states can be estimated exactly. Analytical and simulation results indicate that the signal‐to‐interference ratio (SIR) can be improved effectively after NPSP filtering. The proposed NPSP filter can be implemented in a time‐hopping spread spectrum (TH‐SS) or a direct‐sequence spread spectrum (DS‐SS) UWB system. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
15.
N. Piyachaiyakul C. Charoenlarpnopparut 《Multidimensional Systems and Signal Processing》2013,24(3):435-446
This paper investigates a realization of a three-dimensional (3-D) adaptive notch filter. The procedures are mainly divided into two parts: frequency-detecting and sinusoidal interference removal. The detections are based on adaptive line enhancer on infinite impulse response (IIR) lattice structure. In the interference removal part, a non-separable version of a 3-D notch filter is effectively applied. The magnitude response of a 3-D adaptive IIR notch filter is illustrated. At the end of the paper, the implementation of an IIR notch filter on a 3-D image is also conducted in order to show how to remove a sinusoidal interference superimposed on a 3-D image. 相似文献
16.
On the UWB system coexistence with GSM900, UMTS/WCDMA, and GPS 总被引:14,自引:0,他引:14
Hamalainen M. Hovinen V. Tesi R. Iinatti J.H.J. Latva-aho M. 《Selected Areas in Communications, IEEE Journal on》2002,20(9):1712-1721
This paper evaluates the level of interference caused by different ultra-wideband (UWB) signals to other various radio systems, as well as the performance degradation of UWB systems in the presence of narrowband interference and pulsed jamming. The in-band interference caused by a selection of UWB signals is calculated at GSM900, UMTS/wideband code-division multiple-access (WCDMA), and Global Position System (GPS) frequency bands as a function of the UWB pulsewidth. Several short-pulse waveforms, based on the Gaussian pulse, can be used to generate UWB transmission. The two UWB system concepts studied here are time hopping and direct sequence spread spectrum. Baseband binary pulse amplitude modulation is used as the data modulation scheme. Proper selection of pulse waveform and pulsewidth allows one to avoid some rejected frequency bands up to a certain limit. However, the pulse shape is also intertwined with the data rate demands. If short-pulses are used in UWB communication the high-pass filtered waveforms are preferred according to the results. The use of long pulses, however, favors the generic Gaussian waveform instead. An UWB system suffers most from narrowband systems if the narrowband interference and the nominal center frequency of the UWB signal overlap. This is proved by bit-error rate simulations in an additive white Gaussian noise (AWGN) channel with interference at global system for mobile communication (GSM) and UMTS/WCDMA frequencies. 相似文献
17.
In this letter, the performance of multicarrier code-division multiple-access (CDMA) systems is studied in the presence of narrowband interference for future ultra-wideband (UWB) communications. A Nakagami fading channel is assumed, and notch filters along with diversity techniques are used in the multicarrier CDMA receiver. A complete performance analysis of error probability is given. It is shown that when the number of subcarriers jammed by narrowband interference is small, the multicarrier receiver without notch filters can work well, due to the gain of frequency diversity from nonjammed subcarriers. On the other hand, when the number of subcarriers jammed by the narrowband interference is large, using notch filters can improve the multicarrier system performance significantly. 相似文献