Channel measurement and feedback method based on cognitive radio technology

Abstract

In an existing millimeter-wave MIMO (Multiple Input Multiple Output) system, in order to execute relatively accurate beam forming or spatial multiplexing, commonly, a reference signal needs to be sent on a working frequency band of the system; after estimation, frequency domain, spatial dimension and intensity state information of a channel, which is changed along time, i.e. CSI (Channel State Information); and feedback is carried out. However, the scheme has the problems that a big error is easy to generate for a system which cannot meet channel reciprocity, a certain system cost is brought in, and flexibility of system capacity and resource allocation is influenced. Therefore, the invention discloses a channel measurement and feedback method based on a cognitive radio technology. An idle frequency band is detected near the working frequency band of the system, and according to channel correlation and an idle frequency band available resource condition, channel measurement or feedback of the CSI is flexibly selected to be executed on the idle frequency band or the working frequency band, so that cost on the working frequency band of the system is reduced, and spectral efficiency, reliability and coverage are improved.

Description

1. Technical field [0001] The present invention relates to the field of communication technology, in particular to a method for channel measurement and feedback based on cognitive radio technology in a wireless communication system. 2. Technical background [0002] In existing multi-antenna systems, reliable channel measurement and feedback methods are generally required in order to perform more accurate beamforming. Taking the communication between the base station and the mobile station in cellular mobile communication as an example, the downlink beamforming either requires the mobile station to measure the reference signal of the base station and then feed it back, or use channel reciprocity to estimate the downlink channel after the base station measures the transmission of the mobile station . The uplink beamforming also has a similar method. Either way, it is necessary to send a reference signal on the frequency band of service transmission, and calculate and feed ba...

AI Technical Summary

Problems solved by technology

[0003] However, the problem with this method is that for systems where the channel reciprocity cannot be satisfied, such as a frequency division duplex system, or a time division duplex TDD system with channel reciprocity mismatch, it is easy to generate large errors

At the same time, detecting and feeding back channel information on the communication frequency band needs to occupy the resources of this frequency band, which brings a certain amount of system overhead and increases the pressure on the use of frequency resources.

Especially in millimeter-wave multiple-input multiple-output MIMO systems, as the wavelength becomes shorter and the number of antennas increases, in order to complete accurate beamforming, the overhead of channel measurement and feedback will be large, which affects the system capacity and the flexibility of resource allocation.

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