共查询到10条相似文献,搜索用时 46 毫秒
1.
In this letter, P × N-point IFFT is proposed to replace the N-point IFFT and analog frequency conversion in an Orthogonal Frequency Division Multiplexing (OFDM)-based Ultra-WideBand (UWB) system, and a new algorithm, named fast P × N-point IFFT, is designed to reduce the complexity of the P × N-point IFFT in the proposed scheme. 相似文献
2.
Zhang Zaichen Bi Guangguo 《电子科学学刊(英文版)》2007,24(1):116-118
I. Introduction Ultra-WideBand (UWB)[1] is a promising tech-nology to achieve transmission rate up to more than 1Gbps. Orthogonal Frequency Division Mul-tiplexing (OFDM)-based schemes[2,3] receive great interests for high speed UWB transmission. In a typi… 相似文献
3.
Fang Zhi Xiao Wan'ang Shi Yin 《电子科学学刊(英文版)》2008,25(1):1-6
A new fine carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The correlation item is the training sequence instead of the received signal in the new algorithm. Simulation results show that the performance of the new algorithm is 4dB-9dB better than that of Schmidl's algorithm. Coarse frequency offset estimation is also discussed in this paper, which is the improvement of Zhang's method. The estimation range using the improvement method is twice as that using the Zhang's method. Based on the hardware of the receiver and the improved algorithm, a method using Fast Fourier Transform (FFT) is proposed to implement the coarse frequency estimation. The chip area of OFDM system can be reduced by using the proposed method. 相似文献
4.
Improvement and Analysis of Carrier-Interferometry Orthogonal Frequency Division Multiplexing System
HE Jian-hui QUAN Zi-yi MEN Ai-dongSchool of Telecommunication Engineering Beijing University of Posts telecommunications Beijing P. R. China 《中国邮电高校学报(英文版)》2005,12(4)
1IntroductionOrthogonal Frequency Division Multiplexing(OFDM) isknown to be with high spectrumefficiency and effectivein coping with such wireless channel i mpairments asmultipath fading and Inter-Symbol Interference(ISI)[1]. Moreover ,OFDMsystems have become prac-tical toi mplement using Fast Fourier Transform(FFT)techniques[2]thanks to advances in digital signal pro-cessing. Up to the present , OFDMhas been employedin several digital transmission systems , such as AD-SL[3], HIP… 相似文献
5.
Xu Bin Yang Chenyang Bi Guangguo 《电子科学学刊(英文版)》2006,23(4):481-484
The Ultra-WideBand Orthogonal Frequency Division Multiplexing (UWB-OFDM) approach is a promising physical-layer technique for short-range, high data-rate wireless networks. As the occupied bandwidth increases, however, its implementation becomes more and more difficult. In order to make it easier to achieve a UWB-OFDM system, a complexity-reduced Frequency diversity (F-diversity) scheme, Frequency-Time Block Code (FTBC), is presented in this paper. The FTBC halves the sampling rate required by other F-diversity techniques so as to cut down the cost of UWB-OFDM systems with F-diversity to a certain extent. 相似文献
6.
该文提出一种传输时间间隔(TTI,Transform Time Interval)内与传输时间间隔间联合跳频新方法,以解决EUTRA(Evolved UMTS Terrestrial Radio Access)上行链路多颗粒度用户及混合重传情况下跳频的问题。该方法根据用户的带宽需求与拉丁方计算得出跳频序列,控制子载波映射时各用户的子载波分配。这个方法适合任意传输带宽需求,既能保持系统单载波传输特性,又能避免数据包之间发生碰撞。仿真结果证明了其有效性。该方法在EUTRA上行链路中具有很好的应用前景。 相似文献
7.
针对基于分数阶Fourier变换的OFDM系统(简称FrFT-OFDM系统)的高峰均功率比(PAPR)问题,该文提出一种低复杂度的峰均比抑制算法。通过对随机相位序列采用周期延拓至FrFT-OFDM符号长度,相位因子加权后与子载波调制前的数据相乘的方式,实现对高峰均比的有效抑制。该算法只需要一次逆离散分数阶Fourier变换(IDFrFT),所有备选信号直接通过时域chirp圆周移位的加权和得到。仿真结果表明,当备选信号个数相同时,该算法与选择映射(SeLecting Mapping, SLM)算法的PAPR抑制性能相当,比部分传输序列(Partial Transmit Sequence, PTS)算法具有更好的PAPR抑制性能,同时,该算法较SLM和PTS算法的运算量降低。 相似文献
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A pilot-aided Orthogonal Frequency Division Multiplexing (OFDM) frequency offset estimator designed for satellite communication system is proposed in the paper. The estimator focuses on the acquisition of the integer part of carrier frequency offset and the acquisition range is as large as the whole signal bandwidth. Making full use of the phase difference between received pilot and local referential pilot, a fast estimation is obtained. Compared with existing method, our method can also work well even in SNR as low as 0dB. Simulations verify the good performance of our method. 相似文献
10.
DuZheng ZhuJinkang 《电子科学学刊(英文版)》2003,20(6):423-430
The frequency offset information is extracted from local pilot amplitude characteristics, which suffer much less distortion in frequency-selective fading channels than those utilizing frequency domain correlation techniques. Simulation shows that the performance of this scheme has better performance than the existing frequency domain pilot-based frequency offset detection scheme. 相似文献