Unbalanced resource distributing method for transmitting layered compressed information sources in COFDM system

Abstract

The invention provides an unbalanced resource distributing method for transmitting layered compressed information sources in a COFDM system. The method comprises the steps of resolving the compressed information sources into two sub layers, respectively calculating out a resource distributing scheme and expected reestablishment distortion before the compressed information sources are resolved and a resource distributing scheme and expected reestablishment distortion after the compressed information sources are resolved, comparing the expected reestablishment distortion before the compressed information sources are resolved with the expected reestablishment distortion after the compressed information sources are resolved, storing the resource distributing scheme before the compressed information sources are resolved if the expected reestablishment distortion before the compressed information sources are resolved is smaller than the expected reestablishment distortion after the compressed information sources are resolved, continuing resolving the layered compressed information sources if the expected reestablishment distortion before the compressed information sources are resolved is not smaller than the expected reestablishment distortion after the compressed information sources are resolved, carrying out recursion on the resolving process until unbalanced resource distribution relying on sub layer resolving cannot obtain smaller expected transmission distortion. Based on the divide and conquer (DC) idea, the method can efficiently distribute subcarriers of level-by-level information source bits and power resources and can reduce expected reestablishment distortion of information sources at the receiving end.

Description

technical field [0001] The invention relates to the technical field of multimedia communication, in particular to a method for allocating unequal weight resources for transmitting layered compressed information sources in a COFDM system. Background technique [0002] Adaptive bit and power resource allocation schemes in classic Orthogonal Frequency Duplex Modulation (OFDM) systems can be divided into two categories: Margin Adaptive (MA) schemes and code rate adaptive ( Rate Adaptive, RA) program. The resource allocation in the MA scheme is to minimize the total power required on the subcarriers through reasonable bit / power allocation under the constraints of a constant total code rate and subcarrier bit error rate. The classic MA scheme mainly includes: Hughes-Hartogs algorithm—according to the greedy optimization idea, select the subcarrier with the smallest required power increment for each information bit in the total code rate layer by layer until all bits are allocated...

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Problems solved by technology

[0003] However, the above scheme cannot be applied to the actual COFDM communication system. First, the impact of channel coding on the resource allocation algorithm is not considered. Second, in the actual wireless multimedia communication system, the total system power is usually constant, and the bit error rate requirement should be adjusted with the signal. The fluctuation and dynamic change of the channel quality, the optimization method based on the MA model in the above scheme obviously does not meet the needs of the actual resource allocation problem

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