Broadband digital beam forming method

Abstract

The invention discloses a digital beam forming method of a broad band, which includes the steps of time division multiplexing quadrature sampling with intermediate frequency, quadrature demodulation, low pass filtering, interpolation delay, phase rotation and beam summation, etc. The beam forming method of the invention puts emphasis on that a single sample circuit is used for carrying out the time division multiplexing quadrature sampling with intermediate frequency on multipath bandpass signals; an FIR wave filter is used for completing the low pass filtering, the interpolation delay and the phase rotation which are matched with the signals at one time to realize the actual formation of delayed beams. As to the executive mode of wave filtering, a multi-channel wave filter with a cascade structure is disclosed. The wave filtering in the same path signal is completed in different filtering submodules by cascading while the different path signals share the same filtering module. The filtering output is completed with the sample selection, and the method of the invention is suitable for being realized in an ASIC or an FPGA and saves a great quantity of logic resources compared with the conventional wave filters.

Description

A Broadband Digital Beamforming Method technical field The invention relates to the fields of radar, sonar and wireless communication, in particular to a broadband digital beam forming method. Background technique Beamforming is a technology widely used in radar, sonar, communication, aerospace and other fields. A beamformer typically works with a sonar transmit or receive array, and it can also work with an electromagnetic wave transmit or receive array. In order to make the sensor array point to one or more specific directions and strengthen the signal from one or more directions, the basic beamforming method is to delay the signal received by each array element according to the beam direction, and then compensate The signals from all channels in the same phase are summed to obtain a beam output pointing in this direction (see Figure 1). In recent years, modern acoustic positioning, high-speed underwater acoustic communication, and acoustic imaging have generally adop...

AI Technical Summary

Problems solved by technology

With the increase of signal frequency and the expansion of array size, the complexity of beamforming system (including data storage, transmission and calculation rate, etc.) will rise sharply, which is the main obstacle restricting the realization of digital beamforming system

In response to the above contradictions, an interpolation beamforming method has been developed. Although this method can reduce the sampling rate requirements, the cost is to increase the operation of zero-padding interpolation and increase the amount of additional calculations.

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