Digital channelizer with arbitrary output sampling frequency

A method of controlling a signal conditioning apparatus receiving primary data from a data source at a primary sample rate and outputting final data at a final sample rate, the method comprising steps of:

• buffering said primary data to form blocks of said primary data;
• outputting said blocks of said primary data to a block filter at a block update rate;
• performing a block filter operation on said blocks of primary data to form output blocks;
• inserting interpolation data into said output blocks to form the final data having a final sample rate that is an integral multiple of said primary sample rate.

A method of separating the combined signals in a frequency division multiple access (FDMA) signal, comprising the steps of:

• digitizing said FDMA signal at a primary sample rate to produce a primary data stream;
• buffering said primary data stream to output said primary data stream in blocks at a block generation rate, each of said blocks being of size 2N, said block generation rate being equal to be a ratio of said primary sample rate and (2N−q), where q is an integer;
• digital-Fourier-transforming said blocks at said block generation rate to produce multiple channel signal streams;
• inserting interpolated data in said multiple channel signal streams at a rate equal to an integral multiple of said block generation rate to produce final multiple channel signal streams.

A method of controlling a polyphase filter having 2N input channels and a shift-register buffer to supply data received from a data source at a rate of Ri to 2N inputs of a Fourier transform computer, said polyphase filter supplying channelized data to a data sink at a rate of Ro, comprising the steps of:

• determining an integer, q, such that (Ro/Ri)(2N−q) is a non-zero integer l;
• commutatingly applying input data from said data source by shift-register buffering said input data laterally across B input channels of a Fourier transform computer;
• Fourier transforming a result of said step of applying at a rate of Ri/(2N−q) to generate channelized data;
• and
• inserting l−1 interpolated data between each successive pair of said channelized data.

A method of controlling a polyphase filter having 2N input channels and a shift-register buffer to supply data received from a data source at a rate of Ri, to 2N inputs of a Fourier transform computer, said polyphase filter supplying channelized data to a data sink at a rate of Ro, the method comprising steps of:

• determining an integer value q such that (Ro/Ri)(2N−q) is a non-zero integer l;
• commutatingly applying input data from said data source by shift-register buffering said input data laterally across 2N input channels of the Fourier transform computer;
• Fourier transforming a result of said step of applying at a rate of Ri/(2N−q) to generate channelized data;
• and
• inserting l−1 interpolated data between each successive pair of said channelized data so that Ro is an integral multiple of a ratio of Ri and (2N−q).

A signal channelizer, comprising:

• a data buffer receiving data sequentially from a data source at an input sampling frequency, the data buffer outputting buffered data in sequential blocks, the sequential blocks of buffered data having overlapping portions of selectable size;
• a block filter receiving the sequential blocks of buffered data at a selectable rate that is independent of a size of the sequential blocks of buffered data and independent of the input sampling frequency, the block filter generating block output data;
• and
• an interpolation filter inserting interpolated data into the block output data and generating an output having an output sampling frequency that is different from an input sampling frequency.

A method of transforming a first signal having a first sample rate to a plurality of second signals each having a second sample rate, the method comprising steps of:

• receiving said first signal;
• separating a first data stream derived from said first signal into a plurality of second data streams at a first data rate, the second data streams including sequential blocks of data having overlapping portions of selectable size;
• converting said plurality of second data streams from said first data rate to a second data rate, the second data rate being independent of a size of the sequential blocks of data and the first sample rate;
• and
• inserting data in said plurality of second data streams to produce said plurality of second signals having said second sample rate, the second sample rate being different from said first sample rate.