OFDM/DMT/ digital communications system including partial sequence symbol processing

• US 20040246890A1
• Filed: 07/02/2004
• Published: 12/09/2004
• Est. Priority Date: 08/22/1996
• Status: Active Grant

• Current Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Original Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Inventors: Marchok, Daniel J., Younce, Richard C., Melsa, Peter J. W.
• Granted Patent: US 8,547,823 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2628 Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators H04L27/2634 takes precedence
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2662 Symbol synchronisation
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/1453 of modulation type

Abstract

A method of managing a signal over a symbol period includes supplying samples of the signal at beginning and end portions of the symbol period. The method further includes suppressing the supply of samples of the signal at a middle portion of the symbol period.

Claims

1. A method of managing a signal over a symbol period comprising:

supplying a first plurality of samples of the signal at beginning and end portions of the symbol period; and

suppressing supply of a second plurality of samples of the signal at a middle portion of the symbol period.

2. The method of claim 1, further comprising temporarily storing the first and the second pluralities of samples.

3. The method of claim 1, further comprising filtering the first plurality of samples.

4. The method of claim 3, wherein filtering further comprises filtering the beginning and the end portions symmetrically.

5. The method of claim 4, wherein filtering symmetrically comprises adding a sample at the beginning portion of the signal to a corresponding symmetric sample at the end portion of the signal.

6. The method of claim 4, wherein filtering symmetrically comprises:

multiplying a coefficient to a sample at the beginning portion of the signal; and

multiplying the coefficient to a corresponding symmetric sample at the end portion of the signal.

7. An apparatus for managing a signal over a symbol period comprising a bypass control that supplies a first plurality of samples of the signal at beginning and end portions of the symbol period and suppresses supplying a second plurality of samples of the signal at a middle portion of the symbol period.

8. The apparatus of claim 7, further comprising a symbol buffer connected to the bypass control that temporarily stores the first and the second pluralities of samples.

9. The apparatus of claim 7, further comprising a filter connected to the bypass control that receives the first plurality of samples.

10. The apparatus of claim 9, wherein the filter is a FIR filter.

11. The apparatus of claim 9, wherein the filter is symmetric.

12. The apparatus of claim 9, wherein the filter comprises symmetric taps.

13. The apparatus of claim 9, wherein the filter comprises an adder that adds a sample at the beginning portion of the signal to a corresponding symmetric sample at the end portion of the signal.

14. The apparatus of claim 9, wherein the filter comprises a multiplier that multiplies a coefficient to a sample at the beginning portion of the signal and multiplies the coefficient to a corresponding symmetric sample at the end portion of the signal.

15. An article of manufacture, including sequences of instructions that, when executed by a processor, causes the processor to perform a method for managing a signal over a symbol period, the method comprising:

supplying a first plurality of samples of the signal at beginning and end portions of the symbol period; and

suppressing supplying a second plurality of samples of the signal at a middle portion of the symbol period.

16. The article of manufacture of claim 15, further comprising temporarily storing the first and the second pluralities of samples.

17. The article of manufacture of claim 15, further comprising filtering the first plurality of samples.

18. The article of manufacture of claim 17, wherein filtering further comprises filtering the beginning and the end portions symmetrically.

19. The article of manufacture of claim 18, wherein filtering symmetrically comprises adding a sample at the beginning portion of the signal to a corresponding symmetric sample at the end portion of the signal.

20. The article of manufacture of claim 18, wherein filtering symmetrically comprises:

multiplying a coefficient to a sample at the beginning portion of the signal; and

multiplying the coefficient to a corresponding symmetric sample at the end portion of the signal.