Efficient channel estimate based timing recovery

• US 20090147895A1
• Filed: 09/11/2007
• Published: 06/11/2009
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: Advanced Receiver Technologies, LLC
• Original Assignee: Advanced Receiver Technologies, LLC
• Inventors: McKown, Russell
• Granted Patent: US 8,279,988 B2
• Time in Patent Office: Days
• US Class Current: 375/354
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/2656 Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe synchronisation
• CPC Class Codes: H04L 27/2662 Symbol synchronisation
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 7/0029 interpolation of received data signal
• CPC Class Codes: H04L 7/0062 detection of error based on data decision error, e.g. Mueller type detection

Abstract

A module and method for channel estimate based timing recovery comprises a timing estimation module, a channel estimation module communicably coupled to the timing estimation module, a conversion module communicably coupled to the timing estimation module and to the channel estimation module, and an analog pulse shaping filter communicably coupled to the conversion module, wherein: the analog pulse shaping filter receives an analog signal and outputs a filtered analog signal, the conversion module receives the filtered analog signal and outputs a 1/T rate signal to the channel estimation module, the channel estimation module outputs a 1/T Channel Impulse Response (CIR) estimate to the timing estimation module, and the timing estimation module outputs a timing estimate to the conversion module, wherein the timing estimate is used in conjunction with an output of the conversion module to provide the 1/T rate signal.

Claims

1. A module, comprising:

a timing estimation module;

a channel estimation module communicably coupled to the timing estimation module;

a conversion module communicably coupled to the timing estimation module and to the channel estimation module; and

an analog pulse shaping filter communicably coupled to the conversion module;

wherein;

the analog pulse shaping filter receives an analog signal and outputs a filtered analog signal;

the conversion module receives the filtered analog signal and outputs a 1/T rate signal to the channel estimation module;

the channel estimation module outputs a 1/T Channel Impulse Response (CIR) estimate to the timing estimation module; and

the timing estimation module outputs a timing estimate to the conversion module, wherein the timing estimate is used in conjunction with an output of the conversion module to provide the 1/T rate signal.

2. The module of claim 1, wherein the output of the conversion module is a digital signal.

3. The module of claim 1, wherein the conversion module is a higher rate analog-to-digital conversion module.

4. The module of claim 1, wherein the 1/T rate signal is at least one of:

a timing optimized output signal; and

a minimum rate signal.

9. The module of claim 1, wherein the 1/T rate signal is at least one of:

a timing optimized output signal; and

a minimum rate signal.

10. The module of claim 1, wherein the 1/T rate signal is sent to a user associated with the module.

5. A module, comprising:

an interpolation filter;

a timing estimation module communicably coupled to the interpolation filter; and

a channel estimation module communicably coupled to the interpolation filter, and to the timing estimation module;

wherein;

the interpolation filter receives a digital signal and outputs a 1/T rate signal to the channel estimation module;

the channel estimation module outputs a 1/T Channel Impulse Response (CIR) estimate to the timing estimation module; and

the timing estimation module outputs a timing estimate to the interpolation filter, wherein the timing estimate is used in conjunction with the digital signal to provide the 1/T rate signal.

6. The module of claim 5 comprising a conversion module communicably coupled to the interpolation filter.

7. The module of claim 6 wherein the conversion module is a higher rate analog-to-digital module.

8. The module of claim 6 wherein the conversion module receives an analog signal.

11. A module, comprising:

an interpolation filter;

a module communicably coupled to the interpolation filter;

a timing estimation module communicably coupled to the interpolation filter; and

a channel estimation module communicably coupled to the module, to the interpolation filter, and to the timing estimation module;

wherein;

the interpolation filter receives a digital signal and outputs a one sample per baud interval (1/T) rate signal to the module and to the channel estimation module;

the channel estimation module outputs a Channel Impulse Response (CIR) estimate to the timing estimation module; and

the timing estimation module outputs a timing estimate to the interpolation filter.

12. The module of claim 11, wherein the module is at least one of:

a signal processing module;

a demodulator module

13. The module of claim 11 wherein the demodulator module outputs data.

14. The module of claim 13 wherein the output data is received by a user.

15. The module of claim 14 wherein the user is associated with the module.

16. A method for determining a timing estimate, comprising:

receiving a 1/T sampled channel waveform estimate;

interpolating the 1/T sampled channel waveform estimate to an N/T sampled channel waveform estimate;

determining an absolute value waveform based on the interpolating; and

determining a timing estimate based on the absolute value waveform.

17. The method of claim 16 comprising outputting the timing estimate to at least one of:

a conversion module;

a timing estimation module;

another timing estimation module;

a timing error detector; and

a timing recovery module.

18. The method of claim 16, wherein N is greater than 1.

19. The method of claim 16, wherein N is around 8 to around 64.

20. The method of claim 16, wherein the 1/T sampled channel waveform estimate is based upon an analog pulse shaped filtered signal.