scholarly journals Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Slavche Pejoski ◽  
Venceslav Kafedziski
Keyword(s):  
Real Time ◽  
Fading Channels ◽  
Video Transmission ◽  
Single Layer ◽  
Rate Distortion ◽  
Wireless Channel ◽  
Video Encoding ◽  
Cross Layer ◽  
Mimo Channels ◽  
Channel Errors

We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

A cross-layer solution for enabling real-time video transmission over IEEE 802.15.4 networks

2010 ◽  
Vol 51 (3) ◽  
pp. 1069-1104 ◽  
Author(s):  
Antonio-Javier Garcia-Sanchez ◽  
Felipe Garcia-Sanchez ◽  
Joan Garcia-Haro ◽  
Fernando Losilla
Keyword(s):  
Real Time ◽  
Video Transmission ◽  
Ieee 802.15.4 ◽  
Cross Layer ◽  
Layer Solution

Cross-Layer Optimization for Energy-efficient QoS Support of Multimedia Streams

2010 ◽  
pp. 113-134
Author(s):  
Carolina Blanch Perez del Notario ◽  
Sofie Pollin ◽  
Tong Gan ◽  
Claude Desset ◽  
Antoine Dejonghe ◽  
...  
Keyword(s):  
Video Quality ◽  
Rate Distortion ◽  
Low Complexity ◽  
Video Codec ◽  
Video Encoding ◽  
Cross Layer ◽  
Portable Devices ◽  
Wireless Video ◽  
Cross Layer Optimization ◽  
Multimedia Streams

A major limitation for wireless video communication on portable devices is the limited energy budget. For this reason, efficient usage of the scarce energy becomes a critical design constraint, in addition to meeting the Quality of Service constraints related to the video quality. In this chapter the authors focus on minimizing the energy cost of the two main energy consumers in the handheld wireless video device: the video encoding and wireless communication tasks. For this purpose, they present a cross-layer approach that explores the tradeoff between coding and communication energies. They then exploit the Rate-Distortion-Complexity tradeoffs and flexibility of the Scalable Video Codec. The results show that by adapting the codec configuration at runtime to the specific scenarios up to 50% of the total energy can be saved with marginal video quality loss. Moreover, the approach presented is of low complexity and easily deployable in practical systems.

scholarly journals ARQ-Aware Scheduling and Link Adaptation for Video Transmission over Mobile Broadband Networks

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Victoria Sgardoni ◽  
David R. Bull ◽  
Andrew R. Nix
Keyword(s):  
Real Time ◽  
Error Rate ◽  
Video Transmission ◽  
Mobile Station ◽  
Transmission Efficiency ◽  
Packet Error Rate ◽  
Mobile Wimax ◽  
Mobile Broadband ◽  
Channel Errors ◽  
Correlated Channel

This paper studies the effect of ARQ retransmissions on packet error rate, delay, and jitter at the application layer for a real-time video transmission at 1.03 Mbps over a mobile broadband network. The effect of time-correlated channel errors for various Mobile Station (MS) velocities is evaluated. In the context of mobile WiMAX, the role of the ARQ Retry Timeout parameter and the maximum number of ARQ retransmissions is taken into account. ARQ-aware and channel-aware scheduling is assumed in order to allocate adequate resources according to the level of packet error rate and the number of ARQ retransmissions required. A novel metric, namely,goodput per frame, is proposed as a measure of transmission efficiency. Results show that to attain quasi error free transmission and low jitter (for real-time video QoS), only QPSK 1/2 can be used at mean channel SNR values between 12 dB and 16 dB, while 16QAM 1/2 can be used below 20 dB at walking speeds. However, these modes are shown to result in low transmission efficiency, attaining, for example, a total goodput of 3 Mbps at an SNR of 14 dB, for a block lifetime of 90 ms. It is shown that ARQ retransmissions are more effective at higher MS speeds.

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