Sporadic channel filtering

摘要

A digital up-converter (DUC) circuit for performing digital channel filtering of an incoming baseband digital signal. The proposed circuit reduces the complexity of the channel module filter of the DUC. This is achieved by taking advantage of the structure of the underlying symbol waveforms carried by the incoming baseband digital signal which have one or more known discontinuities comprising random amplitude and/or phase. Namely, the channel filter module is activated only for the digital samples located around the known discontinuities and is deactivated for the remaining digital samples. Further, the switching of the channel filter module from one state to another can be performed according to a smooth function so that further discontinuities are not introduced in the incoming baseband digital signal. A method and a computer program are also disclosed.

主权项

1. A digital up-converter, DUC, circuit for performing digital channel filtering of an incoming baseband digital signal and up-converting the filtered incoming baseband digital signal into an intermediate Frequency, IF, baseband digital signal, the incoming baseband digital signal comprising digital samples representative of a plurality of contiguous symbols having at least a first discontinuity comprising random amplitude and/or phase, between symbols taken two-by-two, the DUC comprising:
a channel filter module arranged to perform digital channel filtering on the digital samples, the channel filter module having an active mode and a standby mode of operation, wherein:
in the active mode, digital channel filtering is performed; and,in the standby mode, digital channel filtering is not performed; a processing unit, such as a processor, operably coupled to the channel filter module and arranged to set the channel filter module:
in the active mode, for a given number N of digital samples around the first discontinuity; and,in the standby mode, for the remaining digital samples; wherein the given number N of digital samples is substantially lower than the number of digital samples associated with one symbol.