Method and means for transmultiplexing signals between signal terminals and radio frequency channels

• US 5,396,489 A
• Filed: 10/26/1992
• Issued: 03/07/1995
• Est. Priority Date: 10/26/1992
• Status: Expired due to Term

• Current Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Harrison, Robert M.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US07/966,630
• Time in Patent Office: 862 Days
• Field of Search: 370/49.5, 370/50, 370/70, 370/123, 364/724.1, 364/724.13, 364/572, 364/576, 364/577, 364/724.01, 375/103
• US Class Current: 370/210
• CPC Class Codes: H03H 17/0211 using specific transformation algorithms, e.g. WALSH functions, Fermat transforms, Mersenne transforms, polynomial transforms, Hilbert transforms correlation computation G06F17/156
• CPC Class Codes: H03H 17/0251 Comb filters
• CPC Class Codes: H04J 4/005 Transmultiplexing

Abstract

A method and apparatus are provided of transmultiplexing a plurality of signals between a plurality of signal terminals (17 or 29) and a plurality of selected radio frequency channels. The method includes the step of, and apparatus for, frequency translating and filtering the plurality signals between the plurality of selected channels and a polyphase discrete Fourier transform filter bank (16 or 21) within a comb filter (15 or 22). The method further includes the step of frequency division multiplexing the plurality of signals between the plurality of signal terminals and comb filter (15 or 22) within a polyphase discrete Fourier transform filter bank (16 or 21).

Claims

1. A method of multiplexing a plurality of signals between a plurality of signal terminals and a plurality of selected radio frequency channels, such method comprising the steps of:

frequency translating and filtering the plurality or signals within a comb filter between the plurality of selected channels and a discrete Fourier transform filter bank; and

frequency division multiplexing the plurality of signals within the discrete Fourier transform filter bank, wherein said signal terminals are coupled to the discrete Fourier transform filter bank.

2. The method as in claim 1 further including the step of encoding a plurality of signals between the plurality of signal terminals and the plurality of selected channels using a polyphase discrete Fourier transform filter bank as the discrete Fourier transform filter bank and an interpolating comb filter as the comb filter.

3. The method as in claim 1 further including the step of decoding a plurality of output signals between the plurality of selected channels to the plurality of signal terminals using a polyphase discrete Fourier transform filter bank as the discrete Fourier transform filter bank and an interpolating comb filter as the comb filter.

4. An apparatus for multiplexing a plurality of signals between a plurality of signal terminals and a plurality of selected radio frequency channels, such apparatus comprising:

means for frequency translating and filtering the plurality of signals within a comb filter between the plurality of selected channels and a discrete Fourier transform filter bank; and

means for frequency division multiplexing the plurality of signals within, the discrete Fourier transform filter bank, wherein said signal terminals are coupled to the discrete Fourier transform filter bank.

5. The apparatus as in claim 4 further comprising means for encoding a plurality of signals between the plurality of signal terminals and the plurality of selected channels using a polyphase discrete Fourier transform filter bank as the discrete Fourier transform filter bank and an interpolating comb filter as the comb filter.

6. The apparatus as in claim 4 further comprising means for decoding a plurality of output signals between the plurality of selected channels to the plurality of signal terminals using a polyphase discrete Fourier transform filter bank as the discrete Fourier transform filter bank and an interpolating comb filter as the comb filter.

7. A method of decoding a plurality of selected radio frequency channels within a receiver, such method comprising the steps of:

frequency translating and filtering the radio channels using a decimating comb filter; and

producing a plurality of output signals, at a plurality of respective outputs, by filtering the output of the decimating comb filter using a polyphase discrete Fourier transform filter bank.

8. The method of claim 7 further including the step of operating the decimating comb filter using a first decimation factor.

9. The method of claim 8 further including the step of operating the polyphase discrete Fourier transform filter bank using a second decimation factor.

10. The method of claim 9 wherein the product of the first and second decimation factors substantially equals a channel spacing of the selected channels.

11. An apparatus for decoding a plurality of selected radio frequency channels within a receiver, such apparatus comprising:

means for frequency translating and filtering the radio channels using a decimating comb filter; and

means for producing a plurality of output signals, at a plurality of respective outputs, by filtering the output of the decimating comb filter using a polyphase discrete Fourier transform filter bank.

12. The apparatus of claim 11 further comprising means for operating the decimating comb filter using a first decimation factor.

13. The apparatus of claim 12 further comprising means for operating the polyphase discrete Fourier transform filter bank using a second decimation factor.

14. The method of claim 13 wherein the product of the first and second decimation factors substantially equals a channel spacing of the selected channels.