The LZW compression class i mplemented as a fixed length code which you can specify, the huffman algorithm implementation encodes a byte into a variable length bit array. Both of them can work with streams
标签： compression mplemented huffman specify
上传时间： 2013-12-03
上传用户：yzhl1988
This program simulates the bit-error-rate (BER) performance of OSTBC with L=4 antennas over the frequency flat Rayleigh block fading channel The code is developed for real orthogonal design, code rate 1/2 modulation- 16 QAM with gray coding resulting in 2 bits/sec/Hz.
标签： bit-error-rate performance simulates the
上传时间： 2014-01-13
上传用户：whenfly
This project aim was to build wireless software modem for data communication between two computers using an acoustic interface in the voice frequency range (20Hz– 20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz – 20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz – 16,000Hz). The test files used as information files were text files. This goal was attained both in an incoherent scheme and in a coherent scheme. Build under Matlab code, our modem uses OFDM (orthogonal frequency division multiplexing) modulation, synchronization by LMS sequence, channel estimation (no equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of 2 or 4. To optimize the probability of error, these symbols were mapped using Gray mapping. Report
标签： communication computers software wireless
上传时间： 2014-05-29
上传用户：wangdean1101
OFDM Modem Applications • Digital Video Broadcast (DVB) • Digital Audio Broadcast (DAB) • Broadband Wireless Access (802.16x) • Wireless LAN (802.11x & HiperLAN) Orthogonal OFDM Sub-carriers Orthogonal Frequency Division Multiplexing (OFDM)
标签： Broadcast Digital 8226 Applications
上传时间： 2016-03-23
上传用户：cc1
A digital fi‘equeney meter designed with FPGA development software Q-~us 11 is introduced．The 1 Hz—l MHz input measured pulse signals of the digital ii‘equency meter can be used for measuring frequency，period，pulse width and duty ratio，etc．The test results stably display O71 3 seven—segment numeric tubes，and the measuring ranges may be switched over automatically．The measuring error is equal to or less than 0．1％．
标签： development introduced designed software
上传时间： 2016-04-09
上传用户：stewart·
DFT(Discrete Fourier Transformation)是数字信号分析与处理如图形、语音及图像等领域的重要变换工具，直接计算DFT的计算量与变换区间长度N的平方成正比。当N较大时，因计算量太大，直接用DFT算法进行谱分析和信号的实时处理是不切实际的。快速傅立叶变换(Fast Fourier Transformation，简称FFT)使DFT运算效率提高1～2个数量级。其原因是当N较大时，对DFT进行了基4和基2分解运算。FFT算法除了必需的数据存储器ram和旋转因子rom外，仍需较复杂的运算和控制电路单元，即使现在,实现长点数的FFT仍然是很困难。本文提出的FFT实现算法是基于FPGA之上的，算法完成对一个序列的FFT计算，完全由脉冲触发，外部只输入一脉冲头和输入数据，便可以得到该脉冲头作为起始标志的N点FFT输出结果。由于使用了双ram，该算法是流型(Pipelined)的，可以连续计算N点复数输入FFT，即输入可以是分段N点连续复数数据流。采用DIF(Decimation In Frequency)-FFT和DIT(Decimation In Time)-FFT对于算法本身来说是无关紧要的，因为两种情况下只是存储器的读写地址有所变动而已，不影响算法的结构和流程，也不会对算法复杂度有何影响。
标签： Transformation Discrete Fourier DFT
上传时间： 2016-04-12
上传用户：lx9076
// This program measures the voltage on an external ADC input and prints the // result to a terminal window via the UART. // // The system is clocked using the internal 24.5MHz oscillator. // Results are printed to the UART from a loop with the rate set by a delay // based on Timer 2. This loop periodically reads the ADC value from a global // variable, Result.
标签： the measures external program
上传时间： 2013-12-27
上传用户：trepb001
This example demonstrates how the C8051F06x SMBus interface can communicate // with a 256 byte I2C Serial EEPROM (Microchip 24LC02B). // - Interrupt-driven SMBus implementation // - Only master states defined (no slave or arbitration) // - Timer4 used by SMBus for SCL low timeout detection // - SCL frequency defined by <SMB_FREQUENCY> constant
标签： demonstrates communicate C8051F06x interface
上传时间： 2016-04-12
上传用户：hanli8870
在DAB系统中的频率同步，载频同步，参考一下Carrier frequency offset estimation of DAB receiver based on phase reference symbol
上传时间： 2014-11-23
上传用户：songrui
// // Histogram Sample // This sample shows how to use the Sample Grabber filter for video image processing. // Conceptual background: // A histogram is just a frequency count of every pixel value in the image. // There are various well-known mathematical operations that you can perform on an image // using histograms, to enhance the image, etc. // Histogram stretch (aka automatic gain control): // Stretches the image histogram to fill the entire range of values. This is a "point operation," // meaning each pixel is scaled to a new value, without examining the neighboring pixels. The // histogram stretch does not actually require you to calculate the full histogram. The scaling factor // is calculated from the minimum and maximum values in the image.
标签： Sample Histogram Grabber sample
上传时间： 2013-12-15
上传用户：ryb
