CN-121996201-A - Cubic spline interpolation circuit suitable for up-sampling

CN121996201ACN 121996201 ACN121996201 ACN 121996201ACN-121996201-A

Abstract

The invention discloses a cubic spline interpolation circuit suitable for up-sampling, which comprises a data weighting module, a cubic spline interpolation function coefficient generation module, an interpolation calculation module and an interpolation module, wherein the data weighting module is used for carrying out data weighting on signals, calculating to obtain a cubic spline interpolation function coefficient value according to weighted signals, calculating to obtain an interpolation value according to the cubic spline interpolation function coefficient value, and completing interpolation after obtaining the interpolation value. Compared with interpolation modules in other chips, the method does not depend on signal frequency characteristics, has high reusability and smaller area, and has higher practical value.

Inventors

ZHANG BOFANG
QU MING
WEI XUAN
LIU SHUTAO
LI WEIKANG

Assignees

中国电子科技集团公司第五十四研究所

Dates

Publication Date: 20260508
Application Date: 20260113

Claims (3)

1. The cubic spline interpolation circuit suitable for up-sampling is characterized by comprising a data weighting module, a cubic spline interpolation function coefficient generation module, an interpolation calculation module and an interpolation module; The input end of the data weighting module is used for receiving an input signal sig and outputting a weighting signal sig_r of the input signal according to the signal received by the input end; The first input end of the cubic spline interpolation function coefficient generation module is used for receiving an input signal sig, the second input end of the cubic spline interpolation function coefficient generation module is connected with the output end of the data weighting module and used for calculating to obtain a cubic spline interpolation function constant item a output by the first output end according to the input signal sig and a weighting signal sig_r of the input signal, the second output end outputs a cubic spline interpolation function first power coefficient b, the third output end outputs a cubic spline interpolation function second power coefficient c, and the fourth output end outputs a cubic spline interpolation function third power coefficient d; The first, second, third and fourth input ends of the interpolation value calculation module are respectively connected with the first, second, third and fourth output ends of the cubic spline interpolation function coefficient generation module, and are used for outputting interpolation sigint according to the cubic spline interpolation function constant term a, the cubic spline interpolation function first power coefficient b, the cubic spline interpolation function second power coefficient c and the cubic spline interpolation function third power coefficient d; the first input end of the interpolation module is used for receiving an input signal sig, the second input end of the interpolation module is connected with the output end of the interpolation calculation module, and the first input end of the interpolation module is used for outputting an interpolated signal sig_out according to a weighted signal sig_r and an interpolated value sig_int of the input signal.
2. The cubic spline interpolation circuit for up-sampling according to claim 1, wherein the data weighting module comprises a first register, a second register, and a weight acquisition circuit; The input end of the first register and the first input end of the weight acquisition circuit are used as the input end of the data weighting module together, the input end of the second register and the second input end of the weight acquisition circuit are connected with the output end of the first register, the third input end of the weight acquisition circuit is connected with the output end of the second register, and the output end of the weight acquisition circuit is used as the output end of the data weighting module; the weight acquisition circuit is used for acquiring a weight value of input data.
3. The cubic spline interpolation circuit for up-sampling according to claim 1 or 2, wherein the cubic spline interpolation function coefficient generation module comprises a constant term a generation module, a first power coefficient b generation module, a second power coefficient c generation module and a third power coefficient d generation module; The input end of the constant term a generating module is used for receiving an input signal sig, and the first output end of the constant term a generating module is used as the first output end of the cubic spline interpolation function coefficient generating module; The first input end of the first power coefficient b generation module is connected with the second output end of the constant term a generation module, the second input end of the first power coefficient b generation module is connected with the third output end of the constant term a generation module, the third input end of the first power coefficient b generation module is connected with the second output end of the second power coefficient c generation module, the fourth input end of the first power coefficient b generation module is connected with the third output end of the second power coefficient c generation module, and the output end of the first power coefficient b generation module serves as the second output end of the third spline interpolation function coefficient generation module; the input end of the second power coefficient c generation module is connected with the output end of the data weighting module, and the first output end of the second power coefficient c generation module is used as the third output end of the cubic spline interpolation function coefficient generation module; The first input end of the third power coefficient d generation module is connected with the second input end of the second power coefficient c generation module, the second input end of the third power coefficient d generation module is connected with the third output end of the second power coefficient c generation module, and the output end of the third power coefficient d generation module is used as the fourth output end of the third spline interpolation function coefficient generation module.

Description

Cubic spline interpolation circuit suitable for up-sampling Technical Field The invention belongs to the technical field of digital integrated circuits, and particularly relates to a cubic spline interpolation circuit suitable for up-sampling. Background In some chips, it is often necessary to perform up-sampling processing on signals such as audio and image, that is, to increase the sampling rate of the signals by interpolation. The interpolation method of the chip commonly used in the market usually uses the zero interpolation method to complete up-sampling. However, the zero insertion method can cause the generation of image frequency, so that a large amount of area is consumed to complete the design of the related filter, and the filter realized by the method has high requirements on signal frequency characteristics and is difficult to multiplex in different application scenes, thereby greatly increasing development cost and development period. In contrast, the cubic spline interpolation method does not depend on signal frequency characteristics, is simpler in algorithm, and has strong reusability and practical significance. Therefore, it has great market value to study a cubic spline interpolation circuit suitable for chip application. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a cubic spline interpolation circuit suitable for chip application, and aims to solve the problems of large area overhead or low reusability of the interpolation circuit in the chip provided by the prior art. The technical scheme provided by the invention is as follows: A cubic spline interpolation circuit suitable for up-sampling comprises a data weighting module, a cubic spline interpolation function coefficient generation module, an interpolation calculation module and an interpolation module; The input end of the data weighting module is used for receiving an input signal sig and outputting a weighting signal sig_r of the input signal according to the signal received by the input end; The first input end of the cubic spline interpolation function coefficient generation module is used for receiving an input signal sig, the second input end of the cubic spline interpolation function coefficient generation module is connected with the output end of the data weighting module and used for calculating to obtain a cubic spline interpolation function constant item a output by the first output end according to the input signal sig and a weighting signal sig_r of the input signal, the second output end outputs a cubic spline interpolation function first power coefficient b, the third output end outputs a cubic spline interpolation function second power coefficient c, and the fourth output end outputs a cubic spline interpolation function third power coefficient d; The first, second, third and fourth input ends of the interpolation value calculation module are respectively connected with the first, second, third and fourth output ends of the cubic spline interpolation function coefficient generation module, and are used for outputting interpolation sigint according to the cubic spline interpolation function constant term a, the cubic spline interpolation function first power coefficient b, the cubic spline interpolation function second power coefficient c and the cubic spline interpolation function third power coefficient d; the first input end of the interpolation module is used for receiving an input signal sig, the second input end of the interpolation module is connected with the output end of the interpolation calculation module, and the first input end of the interpolation module is used for outputting an interpolated signal sig_out according to a weighted signal sig_r and an interpolated value sig_int of the input signal. Further, the data weighting module comprises a first register, a second register and a weight acquisition circuit; The input end of the first register and the first input end of the weight acquisition circuit are used as the input end of the data weighting module together, the input end of the second register and the second input end of the weight acquisition circuit are connected with the output end of the first register, the third input end of the weight acquisition circuit is connected with the output end of the second register, and the output end of the weight acquisition circuit is used as the output end of the data weighting module; the weight acquisition circuit is used for acquiring a weight value of input data. Further, the generating module of the cubic spline interpolation function coefficient comprises a constant term a generating module, a first power coefficient b generating module, a second power coefficient c generating module and a third power coefficient d generating module; The input end of the constant term a generating module is used for receiving an input signal sig, and the first output end of the constant term a generating module is used