Adaptive hierarchical modulation and service multiplex transmission method in high-speed mobile environment

Abstract

The embodiment of the invention provides an adaptive hierarchical modulation and service multiplex transmission method in a high-speed mobile environment. The method comprises the steps that: a receiving end sends estimated channel state information to a sending end, and the sending end calculates by the channel state information to obtain a conditional probability distribution function of a signal-to-noise ratio of a current time slot; a robustness hierarchical modulation scheme is adopted for a high-speed railway scene, and on the basis of the signal-to-noise ratio of the current time slot,an average bit error rate expression of each bit is obtained; scheduling distribution is carried out on multiple services on the basis of the robustness hierarchical modulation scheme, and bit distribution is carried out according to the received signal-to-noise ratio and a modulation parameter, and an optimal modulation transmission strategy switching table is obtained; an adaptive modulation transmission scheme is executed, and an optimal modulation transmission strategy corresponding to current channel state information is selected from an optimal modulation transmission strategy table; andthe sending end sends data according to the optimal modulation transmission strategy. According to the invention, adaptive and efficient transmission can be implemented, and performance of a mobile communication system can be improved.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to an adaptive layered modulation and service multiplexing transmission method in a high-speed mobile environment. Background technique [0002] Layered modulation is to quantify the channel state into different channel quality levels according to the different service quality requirements of various services, and each channel quantization level corresponds to a specific service quality requirement. Generally, the service quality corresponding to the channel quantization level with good quality is higher, and the service quality corresponding to the channel quantization level with poor quality is lower. Adaptive hierarchical modulation can greatly improve the weight rate sum of multiple services carried by the system through reasonable power allocation and subcarrier allocation based on the channel state information (CSI) obtained by channel estimation. [0003] An a...

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Problems solved by technology

[0004] The disadvantage of the above-mentioned adaptive modulation transmission method in the prior art is: when the wireless transmitter is moving at a high speed (such as a high-speed railway mobile communication system), it is difficult for the transmitter to obtain accurate CSI

The reason comes from two aspects: First, the receiver is affected by factors such as channel estimation error, quantization error, and feedback error, and it is difficult to perform accurate channel estimation; second, the time-varying characteristics of high-speed mobile channels are more obvious, and the receiver will estimate the channel The feedback delay of information feedback to the transmitter will cause the CSI information to expire, and the inability to obtain accurate CSI will cause the transmitter to be unable to select appropriate parameters such as transmission power and modulation mode, so the spectral efficiency of the mobile communication system and the weight and rate of services will be reduced. significantly affected

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