Space time collaboration diversity method in OFDMA system

Abstract

The invention discloses a space-time cooperation diversity method of an OFDMA system, which mainly solves the problem of low performance of the system. The method comprises the following steps: 1. the number of terminals participating in cooperation is determined and a linear dispersion code used in cooperation is appointed; 2. subcarriers in the first stage and the second stage are allocated to every terminal; 3. in the first stage of cooperation, LDC code words are sent to other terminals and a receiving terminal by a terminal n on the allocated subcarriers; 4. the LDC code word information sent by the terminal n is received by a terminal m and whether the receiving is correct is checked, if correctly receiving the information of the terminal n, the terminal m reports system to participate in the cooperation, and otherwise, the terminal m does not participate in the cooperation; 5. the terminals participating in the cooperation and LDC code word line components sent by every terminal are determined; 6. in the second period of cooperation, respective cooperation information is sent by the terminals participating in the cooperation to the receiving terminal; and 7. the received information in the first stage and the received information in the second stage are merged and then decoded by the receiving terminal. The invention has the advantages of low bit error rate and is used for cooperation communication in a wireless network.

Description

technical field [0001] The invention belongs to the technical field of wireless digital communication. In particular, it relates to a cooperative diversity method under an OFDMA system, which is used for cooperative communication in a wireless network. Background technique [0002] In wireless communication, the advantage of space-time coding technology combining space diversity and time diversity is that sending signals from multiple antennas can obtain diversity gain and coding gain at the same time, which greatly improves the frequency band utilization of the system. However, in some cases, it is not suitable to be equipped with multiple antennas. For example, in the uplink of wireless communication, it is difficult to install multiple antennas on the mobile terminal due to the limitations of volume, power consumption and process. , which greatly limits the application of space-time coding technology. In order to solve this problem, a kind of fictitious MIMO technology—...

AI Technical Summary

Problems solved by technology

[0008] In the first stage of cooperation, the existing subcarrier allocation method usually allocates a part of continuous subcarriers to each terminal, so that the code subcomponents of each linear dispersive code transmitted in the first stage experience the same fading, so that When the second stage of cooperation uses linear dispersive codes for space-time cooperation, the receiving end cannot effectively use the information of the first stage and the second stage for joint decoding, which limits the performance improvement of the system

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