A content-based precoding solution designed for JPWL transmission

This paper presents a content-based precoding solution for the transmission of a Wireless JPEG 2000 (JPWL ISO/IEC 15444-11) image. To ensure the Quality of Service (QoS), we exploit the channel diversity with a Closed-Loop MIMO scheme. It relies on the Channel State Information (CSI) knowledge at the transmitter side that diagonalizes a MIMO channel into several hierarchical SISO subchannels. In the proposed scheme, the JPWL codestream is divided into hierarchical quality layers passing through the SISO subchannels. According to this strategy, we propose a new content-based precoding algorithm to maximize the visual quality in reception. This algorithm is compared with the Water Filling (WF) precoder that maximizes the channel capacity. Indeed, we show that WF power allocation is not adapted to ensure QoS of a hierarchical content. We compare precoders' performances on a statistical channel and a realistic time-varying MIMO channel provided by a 3D-ray tracer propagation model. Results show that the proposed approach improves the visual quality.