Mixed precode design method for actual broadband large-scale MIMO system

Abstract

The invention provides a mixed precode design method for an actual broadband large-scale MIMO system. The method comprises the following steps: at a radio frequency end, supposing analog precodes on all the carriers to be equal, and calculating an ideal analog precode matrix by taking maximizing the system spectral efficiency as a criterion and utilizing integrated channel state information; according to the phase shifter characteristic of an actual system, determining the analog precode matrix on each carrier in reality, designing a phase position correcting matrix in a digital domain, correcting phase position deviation of the analog precode on different carriers in reality to approach the ideal analog precode, multiplying the phase position correcting matrix by the analog precode matrix of the phase position deviation occurring on each carrier to obtain the designed analog precode matrix; and designing a digital precode matrix at the base band position by utilizing equivalent low-dimension channel state information, and multiplying by the obtained analog precode to obtain a mixed precode design scheme.

Description

Technical field: [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a hybrid precoding design method for an actual wideband massive MIMO system. Background technique: [0002] Hybrid precoding is a research hotspot in massive MIMO. When the number of antennas is large (hundreds or thousands), it is impossible to equip each antenna with a specific radio frequency link (RF) due to power consumption and cost issues. Then It is very meaningful to study the deployment of massive MIMO with a small amount of RF. Hybrid precoding uses a low-cost phase shifter at the radio frequency to control the phase of the signal on the transmitting antenna to achieve analog precoding, which not only reduces the hardware cost, but also reduces the number of radio frequencies required by the system; at the baseband, the equivalent low-dimensional Channel state information (CSI) controls the amplitude and phase of the signal to realize digit...

AI Technical Summary

Problems solved by technology

On the other hand, in such a high-frequency band, in order to ensure the performance of the system, the processing accuracy of the hardware is very fine, which leads to the high price of millimeter-wave devices, so an intermediate frequency link is required

The common intermediate frequency is 2.75 GHz, which will lead to a bandwidth-to-carrier frequency ratio close to 0.5 to 1.5, so the impact of phase offset on analog precoding becomes non-negligible

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