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.
標簽： frequency-domain interpolation performance Design kbit_s speech coder based and of
上傳時間： 2018-04-08
上傳用戶：kilohorse
DESCRIPTION The Texas Instruments MSP430 family of ultra-low-power microcontrollers consists of several devices featuring different sets of peripherals targeted for various applications. The architecture, combined with five low-power modes, is optimized to achieve extended battery life in portable measurement applications. The device features a powerful 16-bit RISC CPU, 16-bit registers, and constant generators that contribute to maximum code efficiency. The digitally controlled oscillator (DCO) allows wake-up from low-power modes to active mode in less than 1 μs. The MSP430G2x13 and MSP430G2x53 series are ultra-low-power mixed signal microcontrollers with built-in 16- bit timers, up to 24 I/O capacitive-touch enabled pins, a versatile analog comparator, and built-in communication capability using the universal serial communication interface. In addition the MSP430G2x53 family members have a 10-bit analog-to-digital (A/D) converter. For configuration details see Table 1. Typical applications include low-cost sensor systems that capture analog signals, convert them to digital values, and then process the data for display or for transmission to a host system.
上傳時間： 2018-12-25
上傳用戶：ygyh
% Computation of ST-ZCR and STE of a speech signal. % % Functions required: zerocross, sgn, winconv. % % Author: Nabin Sharma % Date: 2009/03/15 [x,Fs] = wavread('so.wav'); % word is: so x = x.'; N = length(x); % signal length n = 0:N-1; ts = n*(1/Fs); % time for signal % define the window wintype = 'rectwin'; winlen = 201; winamp = [0.5,1]*(1/winlen);
標簽： 短時過零率和短時能量
上傳時間： 2019-09-23
上傳用戶：minwenji
ephraim1995 子空間降噪經(jīng)典算法
標簽： Enhancement Approach Subspace Signal Speech for
上傳時間： 2020-04-29
上傳用戶：LacrimosaMozart
The concept of smart cities emerged few years ago as a new vision for urban development that aims to integrate multiple information and communication technology (ICT) solutions in a secure fashion to manage a city’s assets. Modern ICT infrastructure and e-services should fuel sustainable growth and quality of life, enabled by a wise and participative management of natural resources to be ensured by citizens and government. The need to build smart cities became a requirement that relies on urban development that should take charge of the new infrastructures for smart cities (broadband infrastructures, wireless sensor networks, Internet-based networked applications, open data and open platforms) and provide various smart services and enablers in various domains including healthcare, energy, education, environmental management, transportation, mobility and public safety.
上傳時間： 2020-05-25
上傳用戶：shancjb
The Internet of Things is considered to be the next big opportunity, and challenge, for the Internet engineering community, users of technology, companies and society as a whole. It involves connecting embedded devices such as sensors, home appliances, weather stations and even toys to Internet Protocol (IP) based networks. The number of IP-enabled embedded devices is increasing rapidly, and although hard to estimate, will surely outnumber the number of personal computers (PCs) and servers in the future. With the advances made over the past decade in microcontroller,low-power radio, battery and microelectronic technology, the trend in the industry is for smart embedded devices (called smart objects) to become IP-enabled, and an integral part of the latest services on the Internet. These services are no longer cyber, just including data created by humans, but are to become very connected to the physical world around us by including sensor data, the monitoring and control of machines, and other kinds of physical context. We call this latest frontier of the Internet, consisting of wireless low-power embedded devices, the Wireless Embedded Internet. Applications that this new frontier of the Internet enable are critical to the sustainability, efficiency and safety of society and include home and building automation, healthcare, energy efficiency, smart grids and environmental monitoring to name just a few.
標簽： Embedded Internet Wireless 6LoWPAN The
上傳時間： 2020-05-26
上傳用戶：shancjb
This introduction takes a visionary look at ideal cognitive radios (CRs) that inte- grate advanced software-defined radios (SDR) with CR techniques to arrive at radios that learn to help their user using computer vision, high-performance speech understanding, global positioning system (GPS) navigation, sophisticated adaptive networking, adaptive physical layer radio waveforms, and a wide range of machine learning processes.
標簽： Technology Cognitive Radio
上傳時間： 2020-05-26
上傳用戶：shancjb
The telecommunications industry is undoubtedly in a period of radical change with the advent of mobile broadband radio access and the rapid convergence of Internet and mobile services. Some of these changes have been enabled by a fundamental shift in the underlying technologies; mobile networks are now increasingly based on a pure Internet Protocol (IP) network architecture. Since the first edition of this book was published in 2009, a multitude of connected devices from eBook readers to smartphones and even Machine-to-Machine (M2M) technologies have all started to benefit from mobile broadband. The sea change over the last few years is only the beginning of a wave of new services that will fundamentally change our economy, our society, and even our environment. The evolution towards mobile broadband is one of the core underlying parts of this revolution and is the focus of this book.
標簽： Networks Packet EPC and 4G
上傳時間： 2020-05-27
上傳用戶：shancjb
Transmit power in wireless cellular networks is a key degree of freedom in the management of interference, energy, and connectivity. Power control in both uplink and downlink of a cellular network has been extensively studied, especially over the last 15 years, and some of the results have enabled the continuous evolution and significant impact of the digital cellular technology.
標簽： Cellular Networks Wireless Control Power in
上傳時間： 2020-05-31
上傳用戶：shancjb
Quality of Service ( QoS ) has always been in a world of its own, but as the technology has been refi ned and has evolved in recent years, QOS usage has increased to the point where it is now considered a necessary part of network design and operation. As with most technologies, large - scale deployments have led to the technology becoming more mature, and QOS is no exception.
標簽： QOS-Enabled Networks
上傳時間： 2020-05-31
上傳用戶：shancjb
蟲蟲下載站版權(quán)所有 京ICP備2021023401號-1
