Digital up converter capable of performing resampling of random multiples

Abstract

The invention discloses a digital up converter capable of performing resampling of random multiples. The digital up converter is used for receiving i and q paths of baseband signals, performing digital up conversion on the two paths of baseband signals and outputting an intermediate frequency signal obtained after processing to a DAC, the digital up converter comprises a forming filter, a resampling module and a frequency mixing module, wherein the resampling module performs resampling on the base bands i and q, can realize up sampling rate conversion of random multiples and can flexibly change the sampling rates of the baseband signals, the adaptability of the sampling rate of the intermediate frequency signal obtained by the frequency mixing module by performing i/q adjustment on the i and q paths of baseband signals is high, which is beneficial for the selection and calibration of the sampling rate of the DAC, moreover the digital up converter does not need to use a CIC filter, a half band filter or a CIC compensation filter, therefore the structure is simple, and the implementation hardware and software is facilitated.

Description

Technical field [0001] This application relates to the field of digital up-converters, and in particular to a digital up-converter capable of resampling at any multiple. Background technique [0002] Digital up-conversion (DUC) is a key digital signal processing module located between the baseband signal processing module and the high-speed DAC in the radio transmission chain. The baseband signal is up-sampling processing by a certain proportion, and after the digital quadrature mixing The baseband signal is converted into a digital intermediate frequency signal, and then converted into an analog signal by a DAC. After further mixing, the signal is transmitted by the antenna. [0003] The implementation process of the existing digital up-conversion technology is generally as follows figure 1 As shown, after the input i and q two-way baseband signals are shaped and filtered, they are up-sampled through a one-stage half-band filter or a multi-stage half-band filter, and then through ...

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Problems solved by technology

[0004] Due to the combination of the half-band filter and the CIC filter in the prior art to achieve a larger proportion of upsampling, it can only support integer multiples of resampling. In this way, the sampling rate of the baseband signal and the sampling rate of the DAC will be selected and Calibration brings certain restrictions; and due to the combination of half-band filter and CIC filter, the upsampling multiples that can be supported are limited, and generally only a limited number of upsampling multiples can be supported; also due to the use of CIC filtering However, because of the inconsistency of the passband gain of the CIC filter, it is often necessary to add a compensation filter behind the CIC filter to compensate for the unevenness of the passband of the CIC filter, which limits the actual design and implementation. Increased complexity and workload

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