Hardware implementation for channel equalization of MIMO-OFDM (multiple-input multiple-output and orthogonal frequency division multiplexing) system

Abstract

The invention provides a hardware implementation method for channel equalization of an MIMO-OFDM (multiple-input multiple-output and orthogonal frequency division multiplexing) system. A Givens rotation-based QR decomposition method is provided and is applicable to a channel equalization module of the MIMO wireless system under the IEEE802.11ac protocol. A traditional matrix inversion hardware implementation method based on a block inversion idea involves mass second-order matrices and a calculation module of a complex multiplication and is only available to non-singular matrices. When the traditional QR decomposition method is used in matrix inversion, CORDIC (coordinated rotation digital computing) and SQUARE ROOT are involved, and many hardware resources are consumed. The invention provides a modified algorithm; matrix QR decomposition is achieved by a modified Givens rotation method to obtain a matrix inversion result. The hardware implementation method has the advantages that matrix inversion can be performed in a pipeline form, the use of coordinated rotation digital computing and square root is avoided, expenditure on the hardware resources is reduced, and a MIMO channel equalization process is implemented efficiently.

Description

technical field [0001] The invention is applied in the technical field of MIMO wireless communication, and specifically relates to a hardware implementation method of matrix inversion based on QR decomposition, which provides a basis for channel equalization of a MIMO receiver. Background technique [0002] The MIMO (Multiple-Input Multiple-Output) system is adopted in the fourth-generation mobile communication technology standards, and has also been widely used in high-speed wireless local area network (WLAN) standard protocols, such as IEEE802.11n / ac protocols. attached figure 1 Shown is the frame structure of the IEEE802.11ac protocol, in which the L-STF and L-LTF fields are used for the frame synchronization process and symbol synchronization process of the received signal respectively; after synchronization, the signal data is transformed into the frequency domain through FFT; VHT- The LTF field contains the length of n OFDM symbols (n represents the number of spatial ...

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Problems solved by technology

However, this method can only realize the inversion process of reversible matrices. When encountering a singular matrix or an approximate singular matrix, the correct result cannot be obtained.

In the actual communication environment, the channel matrix will change with the change of the environment, and the system cannot guarantee the reversibility of the channel matrix. Therefore, the high-order matrix block inversion method is far from enough for the actual wireless communication system

The traditional QR decomposition method breaks the matrix reversibility requirement of the matrix block inversion method, but for the MIMO receiver, the transmission rate is an important parameter to measure the performance of the wireless communication system, and the traditional QR decomposition method realizes the matrix inversion. The performance of the process is not outstanding in this respect, which limits the high throughput transmission performance of the MIMO system

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