We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation, phase-shift keying, and pulse amplitude modulation communications systems.We study the performance of a standard CFO estimate, which consists of first raising the received signal to the Mth power, where M is an integer depending on the type and size of the symbol constellation, and then applying the nonlinear least squares (NLLS) estimation approach. At low signal-to noise ratio (SNR), the NLLS method fails to provide an accurate CFO estimate because of the presence of outliers. In this letter, we derive an approximate closed-form expression for the outlier probability. This enables us to predict the mean-square error (MSE) on CFO estimation for all SNR values. For a given SNR, the new results also give insight into the minimum number of samples required in the CFO estimation procedure, in order to ensure that the MSE on estimation is not significantly affected by the outliers.
標簽： frequency-offset estimation quadrature amplitude
上傳時間： 2014-01-22
上傳用戶：牛布牛
In this project we analyze and design the minimum mean-square error (MMSE) multiuser receiver for uniformly quantized synchronous code division multiple access (CDMA) signals in additive white Gaussian noise (AWGN) channels.This project is mainly based on the representation of uniform quantizer by gain plus additive noise model. Based on this model, we derive the weight vector and the output signal-to-interference ratio (SIR) of the MMSE receiver. The effects of quantization on the MMSE receiver performance is characterized in a single parameter named 鈥漞quivalent noise variance鈥? The optimal quantizer stepsize which maximizes the MMSE receiver output SNR is also determined.
標簽： mean-square multiuser receiver project
上傳時間： 2014-11-21
上傳用戶：ywqaxiwang
This simulation script set allows for an OFDM transmission to be simulated. Imagetx.m generates the OFDM signal, saving it as a windows WAV file. This allows the OFDM signal to be played out a sound card and recorded back. Imagerx.m decodes the WAV to extract the data.
標簽： transmission simulation generates simulated
上傳時間： 2013-12-24
上傳用戶：希醬大魔王
信息隱藏軟件Outguess的源碼 Outguess主要用于JPEg圖象的steganography，本軟件來自Outguess的作者Provos，歡迎大家下載研究-Information Hiding Outguess source software is mainly used Outguess JPEG image steganography, this software from Outguess author of Provos, welcomed everyone to download research
標簽： outguess
上傳時間： 2017-03-07
上傳用戶：Liquor
The investigation of the propagation channel is becoming more and more important in mod- ern wireless communication. The demand for spectral efficiency motivates exploitation of all channels that can possibly be used for communications. Nowadays, a common trend for designing physical layer algorithms is to adapt the transceiving strategy, either by maximizing the diversity gains or by utilizing the coherence of the channels to improve the signal-to-noise power ratio.
標簽： Characterization Propagation Channel
上傳時間： 2020-05-31
上傳用戶：shancjb
A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own wireless link. The signal received from the link transmitter may be jammed by the signals received from the other transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all transmitters, except its own transmitter.
標簽： Stochastic Geometry Networks Wireless Volume and II
上傳時間： 2020-06-01
上傳用戶：shancjb
An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The data is split into multiple data streams at the transmission point and recombined on the receive side by another MIMO radio configured with the same number of antennas. The receiver is designed to take into account the slight time difference between receptions of each signal, any additional noise or interference, and even lost signals.
標簽： Understanding_the_Basics_of_MIMO
上傳時間： 2020-06-01
上傳用戶：shancjb
為了提高超高頻RFID系統中閱讀器在低信噪比的情況下仍具有較高的識別能力,提出一種基于FPGA系統結合軟件無線電方法實現超高頻RFID射頻前端電路方案。超高頻射頻識別系統必須符合EPC Class 1generation 2標準,所設計的電路系統以Xilinx公司的XC6SLX16-2CSG324FPGA芯片為硬件基礎,將數字基帶調制解調和中頻濾波電路在FPGA系統中設計實現,重點闡述了射頻前端電路的設計結構、AD/DA轉換電路,以及數字濾波器的設計。實驗結果表明,所設計的超高頻RFID閱讀器簡化了前端電路系統結構,提升了穩定性,增強了抗干擾能力。該電路系統在信噪比較低的情況下,能夠較好地實現915MHz頻率的射頻接收和發送。In order to improve the reader UHF RFID system still has a higher ability to identify,in the case of low signal-to-noise ratio.The UHF RFID systems must comply with EPC Class 1 generation 2 standard.In this paper,the design of the circuit system based on Xilinx＇s XC6SLX16-2CSG324 FPGA chip,and presents UHF RFID RF front-end circuit with software radio based on FPGA system.Digital baseband modem and IF filter circuit is designed and implemented in the FPGA system,and focused on designing the structure of the RF front-end circuit,AD/DA conversion circuits,and digital filter.Experimental results show that the UHF RFID reader de...
標簽： 915mhz 超高頻 rfid 閱讀 射頻 前端 電路 設計
上傳時間： 2022-04-17
上傳用戶：shjgzh
數字信號處理與噪音抑制Advanced Digital Signal Processing and Noise Reduction,這個是第二版。
標簽： 數字信號處理
上傳時間： 2013-04-24
上傳用戶：Avoid98
·詳細說明：雙音多頻的DTMF信號編碼程序，產生DTMF信號進行編碼。- The double sound multi- frequencies DTMF signal coded program, produces the DTMF signal to carry on the code.
上傳時間： 2013-04-24
上傳用戶：yangzhiwei
