Research on Deep Space TT&C VLBI Full Spectrum Digital Baseband Conversion Methods

A new VLBI baseband conversion method is proposed for special requirements of full spectrum processing in deep space TTC.The method combines the efficient uniform channelization with the orthogonal mixing,which can realize the processing of certain bandwidth without dead zone and distortion.By clever channelization and change of low-pass prototype filter shape factor,the processing of input signal analysing bandwidth without dead zone and distortion in certain bandwidth is realized.Using the flexibility of orthogonal mixing,wide-band and narrow-band single-sideband output schemes are designed.The center frequency of output signal can be changed arbitrarily and the bandwidth can be selected by different filter cascades.Numerical simulations show that the proposed method is efficient,has less resource consumption and can realize full spectrum baseband conversion of analysing bandwidth.