OFDM多载波系统无线图像的鲁棒性传输

Robust wireless image transmission over OFDM muticarrier system

将图像分级编码与OFDM多载波调制技术相结合,对图像进行分级编码,使经过编码的数据按视觉重要性不同进行排列。然后再根据无线信道的实际衰落情况,为重要性不同的比特分配不同的信道、比特速率和功率,在总的发送功率一定的条件下,以及在满足视觉重要性不同的误比特条件下,使系统的传输速率最大。在上述自适应分配的基础上,根据各子信道传输的比特重要性的不同,采用不同信道编码,实现对视觉重要性高的比特的更高级别的保护,使其在较低的误比特率下进性传输。

The robust image transmission by combining sealable image coding with OFDM（ orthogonal frequency division mutiplexing） modulation was considered. The output bit streams of the scalable image coder have different perceptual importance. It provided unequal error protection to these bit streams by adaptively assigning subchannel, bit rates and power according to instantaneous channel characteristics and maximize the bit rates of the system under a total power constraint and target BER＇ s. Further, if the important bit streams are given higher channel error protections on the basis of above adaptive allocation, the system performance can be improved greatly.