Collaborative diversity method based on constellation rotation quasi-orthogonal space time block code

Abstract

The invention discloses a cooperation diversity method based on a constellation rotation quasi-orthogonal space-time group code, which mainly solves the problem that the transmission rate of a cooperation method of an orthogonal space-time group code is low. The cooperation transmission procedure comprises: during the broadcasting phase, a source node sends broadcast signals to a relay node and adestination node, the relay node performs the coding and the cyclic redundancy check to the received signals, if the cyclic redundancy check is right, the received signals are involved in the cooperation transmission in the space-time cooperation phase, or else the received signals are not involved in the cooperation transmission; during the space-time cooperation phase, the source node and the relay node calibrated right divide transmitted information into two groups for the constellation mapping, respective transmitted information is generated according to the coding matrix of the quasi-orthogonal space-time group code, and is sent to the destination node; the destination node performs the joint maximum likelihood decoding for received signals in the broadcasting phase and the space-time cooperation phase, and divides the decoding result into two groups for the demodulation. The invention has higher space diversity gain under the condition of same spectrum effectiveness and transmission power compared with the cooperation diversity method of the orthogonal space-time group code.

Description

technical field [0001] The invention belongs to the technical field of wireless digital communication, and in particular relates to a cooperative diversity method of quasi-orthogonal space-time block code QOSTBC using constellation rotation, which is used for cooperative communication of multi-node wireless networks. Background technique [0002] 1. Cooperative Diversity Technology [0003] The multipath fading characteristic of the wireless channel is an important bottleneck affecting the transmission rate and quality of wireless communication. How to overcome the multipath effect becomes the primary problem to be solved to improve the communication quality. Diversity technology is an effective way to resist multipath fading, especially space diversity uses different antennas to send signals, so that multiple signal copies that experience independent fading can be obtained at the receiving end to effectively eliminate the influence of multipath fading, and does not require ...

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Problems solved by technology

However, OSTBC with more than 2 antennas can obtain full space diversity gain, but the code rate cannot be guaranteed to be 1.

The maximum code rate of the 3-antenna and 4-antenna OSTBC that can be designed at present is only 3 / 4, and when the number of transmitting antennas is greater than 4, it is difficult to design an OSTBC with a code rate greater than 1 / 2. If it is applied to In the multi-relay cooperative system, the system transmission rate will be low.

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