Window position optimization for pilot-aided OFDM system

• US 8,625,686 B2
• Filed: 07/18/2008
• Issued: 01/07/2014
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Li, Yan, Huang, Feng, Rajagopal, Ravikiran, Schaffer, Troy
• Primary Examiner(s): NGUYEN, LEON VIET Q
• Application Number:
  US12/175,851
• Publication Number:
  US 20100014600A1
• Time in Patent Office: 1,999 Days
• Field of Search: 370/208, 370/252, 375/260, 375/239, 375/340, 375/344, 375/346
• US Class Current: 375/260
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/2662 Symbol synchronisation

Abstract

A window position optimization for a pilot-aided OFDM system is disclosed. A method of reducing aliasing in an orthogonal frequency division multiplexing (OFDM) system, using window optimization and pilots comprises receiving an RF signal including a pilot, generating a channel frequency response estimate, interpolating the channel estimate to calculate a pilot carrier frequency response, and dynamically selecting a window to capture a channel impulse response to prevent aliasing.

Claims

1. A method of reducing aliasing in an orthogonal frequency division multiplexing (OFDM) system, the method comprising:

receiving a signal including a transmission parameter signaling (TPS) signal;

determining a first channel estimate based on the TPS signal;

receiving a continuous pilot signal;

determining a second channel estimate based on the continuous pilot signal;

selecting a first window in which to capture a channel impulse response, wherein the window minimizes a difference between the first channel estimate and the second channel estimate;

determining a channel impulse response based on the first window;

wherein the selecting is performed to capture the channel impulse response to prevent aliasing;

selecting a second window in which to capture a channel impulse response;

determining a second channel impulse response based on the selected second window;

selecting between the first and second windows as a preferred window; and

determining a channel impulse response based on the preferred window.

2. The method of claim 1, further comprising:

shifting the channel impulse response into the selected window.

3. The method of claim 1, wherein the OFDM system is a digital video broadcasting-terrestrial (DVB-T) system.

4. The method of claim 1, wherein the OFDM system is a integrated services digital broadcasting-terrestrial (ISDB-T) system.

5. The method of claim 1, wherein the first pilot signal is a transmission and multiplexing configuration control (TMCC) signal.

6. An orthogonal frequency division multiplexing (OFDM) receiver, the OFDM receiver comprising:

receiving a signal including a transmission parameter signaling (TPS) signal;

determining a first channel estimate based on the TPS signal;

receiving a continuous pilot signal;

determining a second channel estimate based on the continuous pilot signal;

a synchronization and channel estimation (SCE) block configured to receive a signal including a transmission parameter signaling (TPS) signal and to determine a first channel estimate based on the TPS signal, to receive a continuous pilot signal and to determine a second channel estimate based on the continuous pilot signal;

the SCE block further configured to select a first window in which to capture a channel impulse response, wherein the window minimizes the difference between the first channel estimate and the second channel estimate, wherein the SCE block is further configured to determine a channel impulse response based on the first selected window, and wherein the selecting is performed to capture the channel impulse response to prevent aliasing;

the SCE block is further configured to select a second window in which to capture a channel impulse response; and

the SCE block further configured to determine a second channel impulse response based on the second selected window and to select between the first and second windows as a preferred window and then determine a channel impulse response based on the preferred window.

7. The OFDM receiver of claim 6, wherein the SCE block is further configured to shift the channel impulse response into the selected window.

8. The OFDM receiver of claim 6, wherein the OFDM system is a digital video broadcasting-terrestrial (DVB-T) system.

9. The OFDM receiver of claim 6, wherein the OFDM system is a integrated services digital broadcasting-terrestrial (ISDB-T) system.

10. The OFDM receiver of claim 6, wherein the first pilot signal is a transmission and multiplexing configuration control (TMCC) signal.

11. A machine readable storage medium having a stored set of instructions executable by a machine, the instructions when executed are adapted to perform operations comprising:

receiving a signal including a transmission parameter signaling (TPS) signal;

determining a first channel estimate based on the TPS signal;

receiving a continuous pilot signal;

determining a second channel estimate based on the continuous pilot signal;

selecting a first window in which to capture a channel impulse response, wherein the window minimizes a difference between the first channel estimate and the second channel estimate;

determining a channel impulse response based on the first window;

wherein the selecting is performed to capture the channel impulse response to prevent aliasing;

selecting a second window in which to capture a channel impulse response;

determining a second channel impulse response based on the selected second window;

selecting between the first and second windows as a preferred window; and

determining a channel impulse response based on the preferred window.

12. A computer-readable medium containing a first set of instructions adapted to create a processor, wherein the processor is configured to implement a second set of instructions, the second set of instructions comprising:

instructions to receive a signal including a transmission parameter signaling (TPS) signal, to determine a first channel estimate based on the TPS signal, to receive a continuous pilot signal and to determine a second channel estimate based on the continuous pilot signal;

the computer-readable medium further comprising instructions to select a first window in which to capture a channel impulse response, wherein the window minimizes the difference between the first channel estimate and the second channel estimate;

the computer-readable medium further comprising instructions to determine a channel impulse response based on the first window;

wherein the selecting is performed to capture the channel impulse response to prevent aliasing;

the computer-readable medium further comprising instructions to select a second window in which to capture a channel impulse response; and

the computer-readable medium further comprising instructions to determine a second channel impulse response based on the second selected window and to select between the first and second windows as a preferred window and then determine a channel impulse response based on the preferred window.