System and method for enhancing dynamic range of a beamforming multi-channel digital receiver

Abstract

A system and method for enhancing a dynamic range of a beamforming multi-channel digital receiver are described. The receiver comprises a plurality of receiving channels, each including an analog-to-digital converter configured for converting an analog input signal generated by antenna elements into a digital signal. A “spatial” dither signal is used to decorrelate the quantization noise of the analog-to-digital converters. A dither signal is generated and split into a predetermined number of coherent dithering signals. The method includes providing predetermined time delays to the coherent dithering signals, and adding the delayed coherent dithering signals to the input signals in each receiving channel, correspondingly, thereby creating a dither signal equivalent to a signal arriving from a certain specific direction out-of-field-of-view of the antenna array. Removing of the dither signal based on the direction of arrival, is implemented during beamforming signal processing, thus enhancing the dynamic range of electromagnetic signals arriving within a field-of-view of the antenna array.

Description

FIELD OF THE INVENTION[0001]This invention relates to the field of electronically steered antenna techniques, and in particular, to multi-channel receiver systems and methods that use dithering to improve dynamic range performance of multiple analog-to-digital converters.BACKGROUND OF THE INVENTION[0002]Dynamic range is an important characteristic of electronically steered antenna array systems based on a multi-channel digital receiver configured for detecting, processing and estimating parameters of two or more high and low power level signals received from several simultaneously operating emitters. Instantaneous dynamic range of a multi-channel digital receiver operating with signals originating from simultaneously operating plurality transmitters is typically defined as the maximum ratio of the highest and lowest power level signals that may be detected such that the signal parameters can be accurately estimated. Enhancement of the receiver instantaneous dynamic range is increasi...

AI Technical Summary

Benefits of technology

The patent describes a method for improving the dynamic range of a multi-channel digital receiver. The method involves generating a dither signal and splitting it into a number of coherent dithering signals that match the number of receiving channels. This helps to reduce the noise introduced by the analog-to-digital converters in the receiver and improve the signal-to-noise ratio. This method can be applied to both beamforming and mono-bit A / D converters, resulting in a higher dynamic range for the receiver.

Problems solved by technology

However, wideband ADCs with a large number of effective bits usually require high power consumption in signal processing.

Moreover, such ADCs with a high number of quantization levels are usually complex and costly to implement.

Accordingly, implementation of high dynamic range multi-bit wideband ADCs in the multi-channel system, as shown in FIG. 1, is not practical.

However, the dynamic range of ADCs with a low number of bits usually suffers from high level quantization errors that add quantization noise to the output.

As a result of quantization errors, together with high order harmonics of the strong signal, a noise is produced which can cause misdetection of low level signals received simultaneously with high power level signals.

Additionally, these high order harmonics can create false alarm detections.

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