Opportunistic interference alignment method based on limited feedback in wireless mobile communication systems

Abstract

The invention belongs to the technical field of wireless communication and discloses an opportunistic interference alignment method based on limited feedback in a wireless mobile communication system.According to the opportunistic interference alignment method based on the limited feedback in the wireless mobile communication system, precoding matrixes are designed for all users in a cell at a position of a base station; a user scheduling process of an uplink is finished at the position of the base station through adoption of a normalization minimum chordal distance clustering analysis method; scheduled user labels are fed back, and the users in the cell finish establishing the precoding matrixes; and a receiving zero-forcing matrix is designed at each receiving end, thereby finishing a zero-forcing process of a practical interference link. According to the method, through utilization of multiuser classification gain, a transmission rate of the system is clearly improved under the condition that feedback bits are limited and the limitation resulting from the limited feedback is reduced, so the relatively good transmission rate can be achieved under the condition of relatively fewfeedback bits.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to an opportunistic interference alignment method based on limited feedback in a wireless mobile communication system. Background technique [0002] With the development and progress of wireless mobile communication technology, the rapid increase in the number of mobile users and the user's demand for high-speed, high-quality communication make the ability to effectively suppress interference an important factor affecting the performance of future wireless communication systems. The Interference Alignment (IA) technology has been widely concerned by the academic circles because it can suppress the interference while maintaining a linear relationship between the total degree of freedom of the system and the number of users, so that the capacity of the wireless interference network has increased by leaps and bounds. Traditional interference alignment techniques generall...

AI Technical Summary

Problems solved by technology

For the design of the interference alignment scheme in the case of limited feedback, the precoding matrix is ​​usually quantized by the base station and fed back to the transmitter. If there is a certain quantization error, then for the receiving end, the interference signal that has been aligned to the interference signal subspace will spread out again and spread into the entire signal space. At the same time, the quantization feedback precoding matrix will cause the IUI actual link The spatial direction is different from that before quantization. At this time, the original receiving zero-forcing matrix cannot play a good role in suppressing interference and recovering signals.

[0003] To sum up, the problem existing in the existing technology is: in the case of limited feedback of the interference alignment mechanism, the quantized feedback precoding matrix will prevent the ICI from being strictly aligned to the signal subspace of the specified dimension in advance, and the perfect channel state information In this case, the aligned interference signal will spread out again and spread to the entire signal space. At the same time, ICI and IUI cannot be completely zero-forced and eliminated by the original zero-forcing matrix

Its impact on the system, on the one hand, the total residual interference will naturally increase significantly, on the other hand, the total degree of freedom of the system will be lost, and the total transmission rate of the system will be significantly reduced, limiting the throughput of the system and each user Available Spectrum Resources

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