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.
标签： frequency-domain interpolation performance Design kbit_s speech coder based and of
上传时间： 2018-04-08
上传用户：kilohorse
The BTS5016SDA is a one channel high-side power switch in PG-TO252-5-11 package providing embedded protective functions. The power transistor is built by a N-channel vertical power MOSFET with charge pump. The design is based on Smart SIPMOS chip on chip technology. The BTS5016SDA has a current controlled input and offers a diagnostic feedback with load current sense and a defined fault signal in case of overload operation, overtemperature shutdown and/or short circuit shutdown.
上传时间： 2019-03-27
上传用户：guaixiaolong
The contemporary view of the Smart City is very much static and infrastructure- centric, focusing on installation and subsequent management of Edge devices and analytics of data provided by these devices. While this still allows a more efficient management of the city’s infrastructure, optimizations and savings in different do- mains, the existing architectures are currently designed as single-purpose, vertically siloed solutions. This hinders active involvement of a variety of stakeholders (e.g., citizens and businesses) who naturally form part of the city’s ecosystem and have an inherent interest in jointly coordinating and influencing city-level activities.
标签： Internet Systems Cities People Things Smart The and of
上传时间： 2020-05-26
上传用户：shancjb
Today’s wireless services have come a long way since the roll out of the conventional voice-centric cellular systems. The demand for wireless access in voice and high rate data multi-media applications has been increasing. New generation wireless communication systems are aimed at accommodating this demand through better resource management and improved transmission technologies.
标签： Radio Cognitive Software Defined
上传时间： 2020-05-26
上传用户：shancjb
The first Third Generation Partnership Project (3GPP) Wideband Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA networks are deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is expected to be available in the near future. 3GPP has defined the WCDMA operation also for several additional bands, which are expected to be taken into use during the coming years.
标签： HSDPAHSUPA Access Speed Radio UMTS High for
上传时间： 2020-05-27
上传用户：shancjb
This book addresses two aspects of network operation quality; namely, resource management and fault management. Network operation quality is among the functions to be fulfilled in order to offer quality of service, QoS, to the end user. It is characterized by four parameters: – packet loss; – delay; – jitter, or the variation of delay over time; – availability. Resource management employs mechanisms that enable the first three parameters to be guaranteed or optimized. Fault management aims to ensure continuity of service.
标签： Ethernet Networks MPLS and IP
上传时间： 2020-05-27
上传用户：shancjb
For nearly a hundred years telecommunications provided mainly voice services and very low speed data (telegraph and telex). With the advent of the Internet, several data services became mainstream in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks. Today, high-speed data services are already part of our daily lives at work and at home (web surfing, e-mail, virtual private networks, VoIP, virtual meetings, chats...). The demand for high-speed data services will grow even more with the increasing number of people telecommuting.
上传时间： 2020-05-27
上传用户：shancjb
In the nineteenth century, scientists, mathematician, engineers and innovators started investigating electromagnetism. The theory that underpins wireless communications was formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi demonstrated the first wireless transmission. Since then, the range of applications has expanded at an immense rate, together with the underpinning technology. The rate of development has been incredible and today the level of technical and commercial maturity is very high. This success would not have been possible without understanding radio- wave propagation. This knowledge enables us to design successful systems and networks, together with waveforms, antennal and transceiver architectures. The radio channel is the cornerstone to the operation of any wireless system.
标签： LTE-Advanced Generation Next and
上传时间： 2020-05-27
上传用户：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.
标签： QOS-Enabled Networks
上传时间： 2020-05-31
上传用户：shancjb
The following sections profile many of the vendors in the NFV market. The individual profiles were created through a collaborative effort between SDNCentral’s Research Team and the Vendor’s product experts. SDNCentral worked under the assumption the information provided by the vendors was factual, auditing the submissions only to remove unverifiable claims and hyperbole. Extended profiles can be viewed online. While every attempt has been made to validate the capabilities listed in the profiles, SDNCentral advises end users to verify the veracity of each claim for themselves in their actual deployment environments. SDNCentral cannot be held liable for unexpected operations, damages or incorrect operation due to any inaccuracies listed here. SDNCentral welcomes feedback and additional information from end users based on their real-world experiences with the products and technologies listed. The SDNCentral research team can be reached at
标签： SDxCentral-Mega-NFV-Report
上传时间： 2020-06-01
上传用户：shancjb
