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
Digital Control of High-Frequency Switched-Mode Power Converters-Wiley-IEEE Press (2015)
上传时间： 2018-09-15
上传用户：赛德克巴莱
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.
上传时间： 2018-12-25
上传用户：ygyh
895nm Single-Mode VCSEL
上传时间： 2019-05-26
上传用户：jilei
Output Feedback Active Suspension Control With Higher Order Terminal Sliding Mode
标签： 滑模
上传时间： 2019-07-24
上传用户：sjjy0220
Second-Order Consensus in Multiagent Systems via Distributed Sliding Mode Control
上传时间： 2019-07-24
上传用户：sjjy0220
Optimal Guaranteed Cost Sliding-Mode Control of Interval Type-2 Fuzzy Time-Delay Systems
上传时间： 2019-07-24
上传用户：sjjy0220
AO4420, AO4420L ( Green Product ) N-Channel Enhancement Mode Field Effect Transistor
上传时间： 2020-04-19
上传用户：su1254
The General Packet Radio Service (GPRS) allows an end user to send and receive data in packet transfer mode within a public land mobile network (PLMN) without using a permanent connection between the mobile station (MS) and the external network during data transfer. This way, GPRS opti- mizes the use of network and radio resources (RRs) since, unlike circuit- switched mode, no connection between the MS and the external network is established when there is no data flow in progress. Thus, this RR optimiza- tion makes it possible for the operator to offer more attractive fees.
上传时间： 2020-05-27
上传用户：shancjb
A wireless ad-hoc network is a wireless network deployed without any infrastructure. In such a network, there is no access point or wireless router to forward messages among the computing devices. Instead, these devices depend on the ad-hoc mode of their wireless net‐ work interface cards to communicate with each other. If the nodes are within the transmis‐ sion range of the wireless signal, they can send messages to each other directly. Otherwise, the nodes in between will forward the messages for them. Thus, each node is both an end system and a router simultaneously.
上传时间： 2020-06-01
上传用户：shancjb
