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quantization

quantization是在中文中是量化簡(jiǎn)稱，所謂量化，就是把經(jīng)過抽樣得到的瞬時(shí)值將其幅度離散，即用一組規(guī)定的電平，把瞬時(shí)抽樣值用最接近的電平值來表示。

In this project we analyze and design the minimum mean-square error (MMSE) multiuser receiver for un

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(biāo)簽： mean-square multiuser receiver project

上傳時(shí)間： 2014-11-21

上傳用戶：ywqaxiwang
摘　要文章以空間監(jiān)控系統(tǒng)為背景,深入研究了JPEG圖像壓縮標(biāo)準(zhǔn)的實(shí)現(xiàn)方法,并基于FPGA對(duì)其進(jìn)行了實(shí)現(xiàn)和優(yōu)化。文中給出了詳細(xì)的實(shí)現(xiàn)方法和優(yōu)化過程,測(cè)試表明達(dá)到了很好的效果。簡(jiǎn)單介紹了有損靜態(tài)圖

摘　要文章以空間監(jiān)控系統(tǒng)為背景,深入研究了JPEG圖像壓縮標(biāo)準(zhǔn)的實(shí)現(xiàn)方法,并基于FPGA對(duì)其進(jìn)行了實(shí)現(xiàn)和優(yōu)化。文中給出了詳細(xì)的實(shí)現(xiàn)方法和優(yōu)化過程,測(cè)試表明達(dá)到了很好的效果。簡(jiǎn)單介紹了有損靜態(tài)圖像壓縮當(dāng)前有兩種比較流行的標(biāo)準(zhǔn)JPEG和JPEG2000。說明了用JPEG方法壓縮的原因。介紹JPEG基本原理：JPEG對(duì)灰度圖像的壓縮處理過程主要包括:圖像分割,離散余弦變換(DCT),量化(quantization),“Z”形排序(Zigzag Scan),差分脈沖編碼調(diào)制(Differential Pulse Code Modulation,DPCM)對(duì)直流系數(shù)(DC),行程長(zhǎng)度編碼(Run-Length Encoding,RLE)對(duì)交流系數(shù)(AC),霍夫曼(Huffman)編碼等。 JPEG標(biāo)準(zhǔn)的特點(diǎn)是離散余弦變換。比較詳細(xì)介紹壓縮系統(tǒng)的構(gòu)成和實(shí)現(xiàn)。實(shí)現(xiàn)提及步驟， JPEG壓縮模塊設(shè)計(jì)和編碼模塊實(shí)現(xiàn)細(xì)節(jié)。

標(biāo)簽： JPEG FPGA 實(shí)現(xiàn)方法監(jiān)控系統(tǒng)

上傳時(shí)間： 2013-12-25

上傳用戶：410805624
基于頻率插值的4.0kbps 語(yǔ)音編碼器的性能和設(shè)計(jì)（英文）

The 4.0 kbit/s speech codec described in this paper is based on a Frequency Domain Interpolative (FDI) coding technique, which belongs to the class of prototype waveform Interpolation (PWI) coding techniques. The codec also has an integrated voice activity detector (VAD) and a noise reduction capability. The input signal is subjected to LPC analysis and the prediction residual is separated into a slowly evolving waveform (SEW) and a rapidly evolving waveform (REW) components. The SEW magnitude component is quantized using a hierarchical predictive vector quantization approach. The REW magnitude is quantized using a gain and a sub-band based shape. SEW and REW phases are derived at the decoder using a phase model, based on a transmitted measure of voice periodicity. The spectral (LSP) parameters are quantized using a combination of scalar and vector quantizers. The 4.0 kbits/s coder has an algorithmic delay of 60 ms and an estimated floating point complexity of 21.5 MIPS. The performance of this coder has been evaluated using in-house MOS tests under various conditions such as background noise. channel errors, self-tandem. and DTX mode of operation, and has been shown to be statistically equivalent to ITU-T (3.729 8 kbps codec across all conditions tested.

標(biāo)簽： frequency-domain interpolation performance Design kbit_s speech coder based and of

上傳時(shí)間： 2018-04-08

上傳用戶：kilohorse
單片機(jī)實(shí)現(xiàn)ADPCM編碼和解碼

INTRODUCTION In the past, adding speech recording and playback capability to a product meant using a digital signal processor or a specialized audio chip. Now, using a simplified Adaptive Differential Pulse Code Modulation(ADPCM) algorithm, these audio capabilities can be added to any PICmicro device. This application note will cover the ADPCM compression and decompression algorithms, performance comparison of all PICmicro devices, and an application using a PIC16C72 micro-controller.DEFINITION OF TERMS step size -value of the step used for quantization of ana-log signals and inverse quantization of a number of steps.quantization -the digital form of an analog input signal is represented by a finite number of steps.adaptive quantization -the step size of a quantizer is dramatically changed with time in order to adapt to a changing input signal.inverse quantizer -a finite number of steps is converted into a digital representation of an analog signal.

標(biāo)簽： 單片機(jī) adpcm 編碼解碼

上傳時(shí)間： 2022-06-20

上傳用戶：