No abstract

Most multimedia source encoders produce scalable bit streams that are vulnerable to noisy channel effects. Unequal error protection (UEP) designs are attractive solutions for such scalable bit streams. In the other hand, the structure of multiple concatenated codes, which consist of the combination of two or more elementary encoders and interleavers, offers a flexible implementation of unequal data protection. To provide an efficient protection for embedded source bit streams, an adaptive concatenated coding/decoding design is proposed in this paper inspired by serially concatenated turbo codes. This scheme involves iterative decoding of concatenated codes for JPEG 2000 image transmission. In the case of time varying channels, the concatenated coding rates are adaptively chosen to maximize the visual quality. The simulation results show that the proposed scheme achieves better image quality improvements at the receiver side compared with a conventional multiple turbo codes-based design, with significant peak-signal-to-noise ratio gains. INDEX TERMS Scalable bit streams, unequal error protection (UEP), multiple concatenated codes, iterative decoding, JPEG 2000. Recently, [5] proposed a turbo code that provides descending protection capabilities for the data according to their locations

International audienceIn this paper, we investigate a new communication strategy for embedded image transmission over a realistic Multiple-Input Multiple-Output (MIMO) wireless channel. The objective of our approach is to guarantee Quality of Service (QoS) required by the user for all possible channel states. In this scope, two major improvements are considered. The first is based on Unequal Power Allocation (UPA) and aims at optimizing the transmit power over the different antennas in order to maximize the image quality at the reception. The second contribution is based on Joint Source-Channel (JSC) soft-input arithmetic decoding and helps to decrease the error rates at the reception without including extra redundancy. We considered Robust SPIHT (R-SPIHT) source encoder to generate an embedded bit-stream. Simulation results illustrate good image quality improvements at the receiver side, with significant Peak Signal to Noise Ratio (PSNR) gains, especially for a realistic noisy channel provided by a 3D ray-tracing software