Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
34 words
Apparatus for digital signal processing for variable bandwidth signals comprising a bank of contiguous digital filters having overlapping frequency responses which together span the bandwidth of the input signal and sum to unit response.
Claim 2
Dependent Claim
29 words
Apparatus for digital signal processing as claimed in claim 1, comprising a plurality of signal input channels (a) each of which is mixed with a vernier frequency correction (b).
Claim 3
Dependent Claim
33 words
Apparatus for digital signal processing as claimed in claim 1 or 2, comprising a plurality of signal input channels (a) each of which is decomposed into sub-bands using a FFT weighted overlap-add demultiplexer(b).
Claim 4
Dependent Claim
33 words
Apparatus for digital signal processing as claimed in claim 3, in which, for each channel, means (d) are provided for decimating the sub-band outputs by a factor to the common input sampling rate.
Claim 5
Dependent Claim
36 words
Apparatus for digital signal processing as claimed in claim 4, comprising an FFT weighted overlap-add multiplexer (f) and a switch matrix (e) operative to pass the sub-bands from each channel into appropriate ports of the multiplexer.
Claim 6
Dependent Claim
26 words
Apparatus for digital signal processing as claimed in claim 5, in which the FFT weighted overlap-add multiplexer (f) comprises a transform and interpolation by a factor.
Claim 7
Dependent Claim
26 words
Apparatus for digital signal processing as claimed in any of claims 2 to 6, in which the individual input channels are in complex baseband video form.
Claim 8
Independent Claim
45 words
A method of digital signal processing including the steps of feeding an input signal to a bank of contiguous digital filters having overlapping frequency responses which together span the bandwidth of the input signal and subsequently summing individual filter outputs to reconstruct the input signal.
Claim 9
Dependent Claim
25 words
A method of digital signal processing as claimed in claim 8, in which, when the filter outputs are decimated, they are interpolated prior to reconstruction.
Claim 10
Dependent Claim
35 words
A method of digital signal processing as claimed in claim 8 or 9, in which there are a plurality of input channels (a) and each input channel is mixed with a vernier frequency correction (b).
Claim 11
Dependent Claim
36 words
A method of digital signal processing as claimed in claim 8, in which there are a plurality of input channels (a) and each input channel is decomposed into sub-bands using an FFT weighted overlap-add demultiplexer (f).
Claim 12
Dependent Claim
33 words
A method of digital signal processing as claimed in claim 11, in which, for each channel, the sub-band outputs are decimated by a factor to the common input sampling rate of a multiplexer.
Claim 13
Dependent Claim
77 words
A method of digital signal processing as claimed in claim 12, in which the sub-bands from each channel are passed into the appropriate ports of an FFT weighted overlap-add multiplexer (f) by means of a switch matrix (e), the multiplexer performing the function of reconstructing the individual channels, interpolating each channel up to the output sampling rate of the FDM signal, mixing each channel up to its assigned carrier frequency in the FDM and multiplexing the channels.