Forward Error Correction Recovery Research Articles

Performance analysis of packet layer FEC codes and interleaving in FSO channels

The combination of forward-error-correction (FEC) and interleaving can be used to improve free-space optical (FSO) communication systems. Recent research has optimized the codeword length and interleaving depth under the assumption of a fixed buffering size, however, how the buffering size influences the system performance remains unsolved. This paper models the system performance as a function of buffering size and FEC recovery threshold, which allows system designers to determine optimum parameters in consideration of the overhead. The modelling is based on statistics of temporal features of correct data reception and burst error length through the measurement of the channel good time and outage time. The experimental results show good coherence with the theoretical values. This method can also be applied in other channels if a Continuous-Time-Markov-Chain (CTMC) model of the channel can be derived

Estimation of accurate effective loss rate for FEC video transmission

We propose an algorithm for adjusting data transmission parameters, such as the packet size and the code rate of forward error correction (FEC), to obtain maximum video quality under dynamic channel conditions. When determining transmission parameters, it is essential to calculate an accurate effective loss rate that reflects FEC recovery failures and over-deadline packets. To this end, we analyze the delays caused by FEC coding and the potential packet size variations. In our analysis, we consider the effect of delayed transmission of video packets incurred by the parity packets as well as the encoder and decoder buffers. With the analysis reflecting the delay effect, we are able to accurately estimate the delay patterns of all video packets. Based on the analysis results, we establish an accurate model for estimating the effective loss rate. Simulations show that the proposed effective loss rate model accurately estimates the effective loss rate and significantly improves the reconstructed video quality at the receiver.

Video Quality in Transmission over Burst-Loss Channels: A Forward Error Correction Perspective

We evaluate the impact of forward error correction (FEC) coding on the end-to-end video quality of video communications over burst-loss channels. We formulate the probability of a given packet loss pattern and the associated video distortion such that we can compute the expected distortion for the video signal after FEC recovery at the receiver. Using our analytical model, we compute the expected video quality in the case of transmission over different Markov channels, both in the presence or absence of FEC. These results match with high accuracy actual simulation-obtained data thereby validating the proposed analysis.

Optimal choice of Reed-Solomon codes to protect against queuing losses in wireless networks

This article proposes algorithms to determine an optimal choice of the Reed-Solomon forward error correction (FEC) code parameters ( n,k) to mitigate the effects of packet loss on multimedia traffic caused by buffer overflow at a wireless base station. A network model is developed that takes into account traffic arrival rates, channel loss characteristics, the capacity of the buffer at the base station, and FEC parameters. For Poisson distributed traffic, the theory of recurrent linear equations is applied to develop a new closed form solution of low complexity of the Markov model for the buffer occupancy. For constant bit rate (CBR) traffic, an iterative procedure is developed to compute the packet loss probabilities after FEC recovery.

FEC recovery performance for video streaming services over wired-wireless networks

This paper considers the packet recovery performance of forward error correction (FEC) for video streaming services over wired-wireless networks. Focusing on a wireless base station, we model it as a single-server queueing system with a Markovian service process in which the state of the server alternates between Good and Bad states. The system has two independent input processes: one is a general renewal input process and the other is a Poisson arrival process. We analyze the packet- and block-level loss probabilities to investigate the recovery performance of FEC at block level. The analysis is validated with simulation experiments driven by real traffic traces. Numerical examples show that the block-loss probability is greatly affected by the system capacity and the mean Bad-state period, and that the recovery performance of FEC deteriorates according to the fluctuation in the packet transmission rate at a wireless base station.