An adaptive modulation （AM） algorithm is proposed and the application of the adapting algorithm together with low-density parity-check （LDPC） codes in multicarrier systems is investigated. The AM algorithm is base...An adaptive modulation （AM） algorithm is proposed and the application of the adapting algorithm together with low-density parity-check （LDPC） codes in multicarrier systems is investigated. The AM algorithm is based on minimizing the average bit error rate （BER） of systems, the combination of AM algorithm and LDPC codes with different code rates （half and three-fourths） are studied. The proposed AM algorithm with that of Fischer et al is compared. Simulation results show that the performance of the proposed AM algorithm is better than that of the Fischer＇s algorithm. The results also show that application of the proposed AM algorithm together with LDPC codes can greatly improve the performance of multicarrier systems. Results also show that the performance of the proposed algorithm is degraded with an increase in code rate when code length is the same.展开更多
作为一种由ITU-T国际视频组织和ISO的MPEG小组联合推出的未来视频处理标准,JVT(joint video team)的主要功能是改进当前压缩标准,通过采用切图技术、高分辨率的亚像素技术以及不同尺寸的块和形状与使用多个参考图进行Intra/Inter预测编...作为一种由ITU-T国际视频组织和ISO的MPEG小组联合推出的未来视频处理标准,JVT(joint video team)的主要功能是改进当前压缩标准,通过采用切图技术、高分辨率的亚像素技术以及不同尺寸的块和形状与使用多个参考图进行Intra/Inter预测编码等技术来降低码率,提高压缩质量和压缩效率.同时在网络层通过对信息的封装与优先级控制等技术来实现数据在不同网络之间的透明传输与网络友好.重点介绍了JVT草案中的核心技术,包括JVT体系结构、层次模型以及与VCL(video coding layer)和NAL(network abstraction layer)两层相关具有代表性的关键技术,分析和探讨了当前JVT存在的问题和进一步的研究方向.展开更多
基金the National Natural Science Foundation of China (60496313)
文摘An adaptive modulation （AM） algorithm is proposed and the application of the adapting algorithm together with low-density parity-check （LDPC） codes in multicarrier systems is investigated. The AM algorithm is based on minimizing the average bit error rate （BER） of systems, the combination of AM algorithm and LDPC codes with different code rates （half and three-fourths） are studied. The proposed AM algorithm with that of Fischer et al is compared. Simulation results show that the performance of the proposed AM algorithm is better than that of the Fischer＇s algorithm. The results also show that application of the proposed AM algorithm together with LDPC codes can greatly improve the performance of multicarrier systems. Results also show that the performance of the proposed algorithm is degraded with an increase in code rate when code length is the same.
