A Low Complexity Soft Output Spatial Modulation Detection Method

Abstract

The invention provides a low complexity soft output space modulation detection method. The method comprises the following steps: firstly, for each possible transmitting antenna serial number l, mapping a received signal vector y to a channel vector hl direction to obtain a following formula; secondly, generating a quantitative formula according to constellation features and quantizing the following formula to obtain a most probable transmit symbol estimation, as the formula corresponding to each possible transmitting antenna index l; and thirdly, using the hl and the formula to calculate a metric value dl of each antenna-symbol pair, as the formula, so as to sort all antenna-symbol pairs, as the formula according to the dl, and select p antenna-symbol pairs therefrom, as the formula, with the smallest dl to calculate the bit log-likelihood ratio of the transmitting antenna serial number and the transmit symbol, so as to realize the soft output detection of space modulation in the form of log-likelihood ratio. The method reduces the antenna serial numbers and the number of symbols which need to be considered during bit log-likelihood ratio calculation, and greatly reduces the complexity of the detection algorithm of a receiving end of the space modulation technique. By selecting a small p value, the complexity of soft output detection can be further reduced on the basis of sacrificing little performance.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to the receiver signal detection algorithm in the spatial modulation (Spatial Modulation, SM) technology in a Multiple-Input Multiple-Output (MIMO) system, especially a low-complexity Soft output spatial modulation detection method. Background technique [0002] Spatial modulation is a new MIMO transmission technology. Unlike conventional MIMO technology, only one antenna is active in SM technology when information is transmitted each time. Part of the information bits to be sent is used for baseband modulation symbol mapping, and the other part It is used to select the serial number of the active antenna. While ensuring transmission efficiency, SM technology only requires a single radio frequency link, which reduces the complexity and cost of MIMO systems, and also avoids problems such as antenna synchronization and inter-channel interference in MIMO systems. [00...

AI Technical Summary

Problems solved by technology

matched filter method [2][3] Compared with the ML detection algorithm, it can have lower complexity while obtaining better performance, but when the modulation order is higher, the complexity is still higher

Literature [4] proposes a low-complexity detection method independent of the modulation order for the spatial modulation system of the PSK constellation, but this method is not suitable for other constellation types such as QAM, and cannot output soft information to achieve soft output detection

Documents [5-6] proposed soft output SM detection algorithms respectively, and document [7] improved on them, but in order to reduce the complexity, it is first necessary to calculate a custom distance measure, although it can reduce the ML search range , but still need to recalculate the Euclidean distance in ML detection

Generally speaking, the current SM detection algorithm still has certain limitations, especially the soft output spatial modulation detection algorithm, the complexity is still high

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