Real-time ultra-low delay audio coding for wireless transmission

2005 ◽  
Author(s):  
G.Y. Luo
Keyword(s):  
Real Time ◽  
Wireless Transmission ◽  
Audio Coding ◽  
Low Delay

Wavelet Audio Coding by Fixed-Point Short Block Processing for Real-Time Wireless Applications

2012 ◽  
Vol 239-240 ◽  
pp. 1118-1124
Author(s):  
Gao Yong Luo ◽  
Yu Pei Liu
Keyword(s):  
Fixed Point ◽  
Real Time ◽  
Channel Coding ◽  
Error Resilience ◽  
Unequal Error Protection ◽  
Audio Coding ◽  
Block Processing ◽  
Embedded Coding ◽  
Wireless Applications ◽  
Low Delay

Digital audio coding delays have become increasingly critical in real-time wireless applications. In live productions, a codec with ultra low delay is required within the constraints of the available channel bandwidth. However, such a threshold can hardly be reached by means of standard audio coding schemes. To achieve low delay as well as to satisfy cost and power consumption constraints, this paper presents an ultra low delay audio coder by very short block processing and embedded coding implemented in fixed-point DSP. The short block two dimensional (2D) spatial-frequency processing of audio input signal fully exploits the correlation for better compression performance. Lifting wavelet transform with boundary effects minimized by changing wavelet shape is developed using bit shifts and additions to replace multiplications in a fixed-point specification under accuracy constraint. The embedded coding offers the error resilience feature so that joint source-channel coding scheme for unequal error protection can be easily designed by varying both source coding bit rate and channel coding redundancy. Experimental results demonstrate that the proposed coder is efficient and requires less memory in fixed-point computation which guarantees no overflow.

Transfusion Monitoring and Controlling System Based on Wireless Communication

2012 ◽  
Vol 214 ◽  
pp. 579-583
Author(s):  
Jiang Ma ◽  
Yu Qiao Wen ◽  
Ling Yan Du ◽  
Xiao Xiao Liang ◽  
Chong Gang Wei
Keyword(s):  
Communication Network ◽  
Wireless Communication ◽  
Real Time ◽  
Wireless Transmission ◽  
The Core ◽  
Wireless Transceiver ◽  
Controlling System ◽  
Transceiver Module ◽  
Medical Accident

Transfusion monitoring and controlling system of wireless communication is designed for avoidance of medical accident due to inconsiderate care. This system is based on RS-485 bus protocol to build the communication network, consisting of master computer and slave computer. STM32F103R8T6 MCU is the core of the master computer, and MSP430F2132 MCU for slave computer. The wireless transmission of data between master computer and slave computer can be done by nRF905 wireless transceiver module. One new calculation of drop speed is used for better real-time displaying thereof. Provided that abnormal occurrence is during the transfusion, the transfusion tube will be closed by controlling order from system, in order to protect the patient.

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