A Fractional Interpolation Shaping Filter and Its Realization Method

Abstract

The invention provides a fractional-multiple interpolation shaping filter and an implementation method thereof. The fractional-multiple interpolation shaping filter comprises a data synchronization module, a segmented filtering module, a resampling module and a numerically controlled oscillator control module. The numerically controlled oscillator control module generates a slow overflow flag according to baseband modulation rate input and sends the slow overflow flag to the data synchronization module to generate slow synchronous data output; the slow synchronous data output is processed by the segmented filtering module to generate a filter group output; the filter group output and a fast overflow flag as well as the time delay of a fractional time delay filter are processed by the resampling module to generate shaped filtered data. The fractional-multiple interpolation shaping filter is used for realizing fractional-multiple conversion between a user input rate and the rate after interpolation shaping filtering, and is adaptive to the ksps grade real-time adjustment of the user rate and capable of breaking through the traditional limitation on the user input rate; besides, the fractional-multiple interpolation shaping filter is light and ingenious in structure, simple in interface, and high in flexibility and applicability; the fractional-multiple interpolation shaping filter can be migrated to a programmable logic device or designed into a special integrated circuit, and the variable rate range of the filter can be expanded according to requirements.

Description

technical field [0001] The invention belongs to the field of digital signal processing, and in particular relates to a fractional interpolation shaping filter and a realization method thereof, which can be applied to the fields of wireless communication and communication countermeasures. Background technique [0002] In wireless communication systems, in order to effectively use the spectrum, eliminate intersymbol interference and prevent frequency band leakage, the baseband modulated signal must be interpolated and filtered before sending the signal. Based on the ease of implementation of the hardware architecture, the traditional shaping filter adopts an integer multiple interpolation filtering method, and the output data rate after shaping filtering is an integer multiple of the baseband signal data rate. Chinese patents CN1095620C and CN1140063C respectively provide efficient implementation methods of integer multiple interpolation shaping filters. The biggest disadvant...

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Problems solved by technology

[0003] Based on the above purpose, the present invention introduces a fractional interpolation shaping filter and its implementation method. The fractional interpolation shaping filter is used to solve the non-integer multiple relationship between the baseband data rate and the baseband processing clock in the communication system. The problem

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