Method for FDMA signal multiplexing and demultiplexing

A method for demultiplexing a multiplexed input signal into a sequence of frequency division multiple access (FDMA) signals, the method comprising the steps of:

• providing a demultiplexing channelization pattern comprising a plurality of complex channels in a complex channel spectrum;
• aligning the multiplexed input signal contained in a plurality of input channels with the demultiplexing channelization pattern, wherein each of the plurality of input channels are one-half a bandwidth of each of the plurality of complex channels and the plurality of input channels contain a sequence of FDMA signals separated by a reverse sequence of images of the FDMA signals;
• overlaying the plurality of input channels onto the plurality of complex channels such that consecutive even-numbered input channels correspond to consecutive complex channels of the plurality of complex channels;
• and
• extracting the sequence of FDMA signals from the plurality of complex channels.

A method for polyphase filtering a plurality of frequency division multiple access (FDMA) signals to produce a multiplexed output signal, the method comprising the steps of:

• providing a plurality of complex channels corresponding to the plurality of FDMA signals;
• offsetting each of the plurality of FDMA signals relative to each of the plurality of complex channels;
• filtering each of the series of FDMA signals such that each of the series of FDMA signals is centered within and occupies one-half of an available bandwidth in each of the plurality of complex channels, leaving a series of "off" channels such that an "off" channel occurs between each pair of successive FDMA signals in the series of FDMA signals thereby producing said multiplexed output signal;
• and
• processing a real part of the multiplexed output signal such that a plurality of higher frequency signals of the series of FDMA signals image into the series of "off" channels.

A method for polyphase filtering to demultiplex a multiplexed input signal into a sequence of frequency division multiple access (FDMA) signals, the method comprising the steps of:

• providing a demultiplexing channelization pattern comprising a plurality of complex channels in a complex channel spectrum;
• aligning the multiplexed input signal contained in a plurality of input channels with the demultiplexing channelization pattern, wherein each of the plurality of input channels are one-half a bandwidth of each of the plurality of complex channels and the plurality of input channels contain a sequence of FDMA signals separated by a reverse sequence of images of the FDMA signals;
• overlaying the plurality of input channels onto the plurality of complex channels such that consecutive even-numbered input channels correspond to consecutive complex channels of the plurality of complex channels;
• and
• extracting the sequence of FDMA signals from the plurality of complex channels.