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991.
992.
Marco Crepaldi Author Vitae Mario R. Casu Author VitaeAuthor Vitae Maurizio Zamboni Author Vitae 《Integration, the VLSI Journal》2009,42(1):47-60
This works presents an integrated CMOS 2-PPM demodulator based on a switched capacitor network for an energy detection impulse-radio UWB receiver. The circuit has been designed using a top-down methodology that allows to discover the impact of low-level non-idealities on system-level performance. Through the use of a mixed-signal simulation environment, performance figures have been obtained which helped evaluate the influence at system level of the non-idealities of the most critical block. Results show that the circuit allows the replacement of the ADC typically employed in energy detection receivers and provides about infinite equivalent quantization resolution. The demodulator achieves 190 pJ/bit at 1.8 V. 相似文献
993.
The detection performance is evaluated for our proposed analog multiuser receiver in Ul-tra-WideBand (UWB) transmitted-reference system. In the presence of dense multipath and multi-access signals, the performance analysis is difficult due to the complicated waveform of received impulse. We de-velop an approach to analyze the steady-state Signal-to-Interference-plus-Noise (SINR) of the detector out-put. The multipath-spread impulse is fitted to an exponentially decaying profile in the analysis. A closed-form expression of steady-state SINR is further deduced for the proposed Least Minimum Square (LMS) detector. The analysis is validated by simulations in Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) channel re-spectively. Based on the theoretical results, the multipath delay spread is employed to determine the optimal width of the integration window of the detector. 相似文献
994.
In this letter, an ordered successive interference cancellation (OSIC) scheme is applied for multiple‐input multiple‐output (MIMO) detection in ultra‐wideband (UWB) communication systems. The error rate expression of an OSIC receiver on a log‐normal multipath fading channel is theoretically derived in a closed form solution. Its bit error rate performance is analytically compared with that of a zero forcing receiver in the UWB MIMO detection scheme followed by RAKE combining. 相似文献
995.
Hongjun Wang Guangguo Bi 《Frontiers of Electrical and Electronic Engineering in China》2009,4(3):295-299
With the progress of research on cognitive radio in ultra-wideband (UWB) open frequency-band, a joint detection algorithm
integrating the energy and bi-spectrum detection is proposed in detail for non-Gaussian signal detection from Gaussian noise.
The performance of the algorithm was evaluated by simulation, the result of which indicates that the joint detection not only
solves the problem of the signal detection in low signal-to-noise ratio (SNR) but also improves the operational speed and
the detection probability. Thus, the joint detection algorithm has definite prospect in practice. 相似文献
996.
一种应用于6-9GHz UWB系统的低噪声CMOS射频前端设计 总被引:2,自引:2,他引:0
本文介绍了一种应用于6-9 GHz超宽带系统的全集成差分CMOS射频前端电路设计。在该前端电路中应用了一种电阻负反馈形式的低噪声放大器和IQ两路合并结构的增益可变的折叠式正交混频器。芯片通过TSMC 0.13µm RF CMOS工艺流片,含ESD保护电路。经测试得该前端电路大电压增益为23~26dB,小电压增益为16~19dB;大增益下前端电路平均噪声系数为3.3-4.6dB,小增益下的带内输入三阶交调量(IIP3)为-12.6dBm。在1.2V电压下,消耗的总电流约为17mA。 相似文献
997.
Using the hypothesis that data transmitted by different users are statistically independent of each other, this paper proposes a fixed-point blind adaptive multiuser detection algorithm for Time-Hopping (TH) Impulse Radio (IR) Ultra Wide Band (UWB) systems in multipath channel, which is based on Inde-pendent Component Analysis (ICA) idea. The proposed algorithm employs maximizing negentropy criterion to separate the data packets of different users. Then the user characteristic sequences are utilized to identify the data packet order of the desired user. This algorithm only needs the desired user’s characteristic se-quence instead of channel information, power information and time-hoping code of any user. Due to using hypothesis of statistical independence among users, the proposed algorithm has the outstanding Bit Error Rate (BER) performance and the excellent ability of near-far resistance. Simulation results demonstrate that this algorithm has the performance close to that of Maximum-Likelihood (ML) algorithm and is a subopti-mum blind adaptive multiuser detection algorithm of excellent near-far resistance and low complexity. 相似文献
998.
阵列LDPC码构造简单,又易于VLSI实现.文献[4]对其进行了改进,支持任意码长,称为大小兼容的阵列LDPC码(记为SC阵列LDPC码).对于SC阵列LDPC码,本文提出3种改进方法,方法1对文献[4]SC阵列LDPC码进行了完善,排除了因k不是L的因子而产生的错误.方法2、3研究了新的子矩阵排列方法.这些方法对码的距离特性和误码性能都有很大改善.不仅在AWGN信道,还在UWB CM3信道上,通过仿真,证明了其良好性能. 相似文献
999.
1000.
基于子带合成的超宽带雷达杂波建模与仿真 总被引:1,自引:0,他引:1
该文利用子带合成和广义平板模型,分别在不同的入射角和相对带宽条件下进行超宽带雷达地杂波建模、仿真,并对杂波统计特性进行分析.首先根据地形将地面划分成若干个小区域(称为广义平板);把超宽带信号划分成一系列子带(窄带);然后得出各子带信号在平板模型下的杂波反射系数(),最后通过子带合成的方法获得超宽带雷达地杂波模型.通过仿真发现,超宽带雷达地杂波随着入射角或相对带宽变化时,杂波的统计分布也跟随变化;但超宽带雷达杂波的概率密度函数曲线具有"低重心和重拖尾"的共性,且随着相对带宽的增加,拖尾加重.仿真结果证明了"频率分割子带合成"法的可行性. 相似文献