Velocity estimation apparatus and method

• US 20050267370A1
• Filed: 05/31/2005
• Published: 12/01/2005
• Est. Priority Date: 05/29/2004
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd., Yonsei University
• Original Assignee: Samsung Electronics Co. Ltd., Yonsei University
• Inventors: Kim, Ho-Jin, Kim, Eung-Sun, Lee, Jong-Hyeuk, Hong, Dae-Sik, Lee, Ye-Hoon, Park, Goo-Hyun
• Application Number:
  US11/141,178
• Publication Number:
  US 20050267370A1
• Time in Patent Office: Days
• US Class Current: 600/454
• CPC Class Codes: G01S 11/10 using Doppler effect

Abstract

A velocity estimation apparatus and method for a communication system including a transmitter for transmitting signals through wireless channels and a receiver for receiving the signals and restoring data. The apparatus includes a pilot signal detector for detecting a pilot signal from a received signal, a maximum Doppler frequency estimator for estimating a maximum Doppler frequency using the pilot signal detected by the pilot signal detector, and an adaptive type band-limit filter having a limit band based on a previous output value of the maximum Doppler frequency estimator. By using the pilot signal, which is removed with noise, while passing through the band-limit filter, it is possible to precisely estimate a maximum Doppler frequency, and thereby estimate the velocity.

Claims

1. A velocity estimation apparatus for a communication system including a transmitter for transmitting a signal through at least one wireless channel and a receiver for receiving the signal and restoring data, the apparatus comprising:

a pilot signal detector for detecting a pilot signal;

a maximum Doppler frequency estimator for estimating a maximum Doppler frequency using the pilot signal detected by the pilot signal detector; and

an adaptive type band-limit filter for limiting a band in conformity with a previous output value of the maximum Doppler frequency estimator.

2. The apparatus as claimed in claim 1, further comprising:

a velocity information generator for converting the maximum Doppler frequency estimated by the maximum Doppler frequency estimator into velocity information.

3. The apparatus as claimed in claim 1, wherein the estimated maximum Doppler frequency is fed back to the adaptive type band-limit filter through a separate feedback line.

4. The apparatus as claimed in claim 1, wherein the adaptive type band-limit filter is established with a limit band corresponding to {square root}{square root over ( 3/2)} times a previously estimated maximum Doppler frequency.

5. The apparatus as claimed in claim 1, wherein the maximum Doppler frequency estimator uses at least one of a zero-crossing-rate (ZCR), a level-crossing-rate (LCR), an auto-correlation function (ACF), and a covariance (COV) of a received signal, for estimating the maximum Doppler frequency.

6. A velocity estimation apparatus for a mobile communication system including at least one base station for providing at least one mobile station within a service area with wireless access services, the apparatus comprising:

an RF processing unit for down-converting a received wireless signal into a baseband signal;

a sampling unit for sampling a predetermined section of the baseband signal output from the RF processing unit and outputting a digital signal corresponding to the sampled section;

a pilot signal detection unit for detecting a pilot signal from the digital signal output from the sampling unit;

an adaptive type band-limit unit for passing only the pilot signal among signals output from the pilot signal detection unit;

a maximum Doppler frequency estimation unit for estimating a maximum Doppler frequency using the pilot signal filtered by the adaptive type band-limit unit; and

a velocity information generating unit for converting a maximum Doppler frequency value estimated by the maximum Doppler frequency estimation unit into velocity information.

7. The apparatus as claimed in claim 6, wherein the band-limit unit is adaptively established with a limit band based on a previous estimation value of maximum Doppler frequency estimated by the maximum Doppler frequency estimation unit.

8. The apparatus as claimed in claim 7, wherein the limit band corresponds to {square root}{square root over ( 3/2)} times the previous estimation value of maximum Doppler frequency.

9. The apparatus as claimed in claim 6, wherein the maximum Doppler frequency estimation unit uses at least one of a zero-crossing-rate (ZCR), a level-crossing-rate (LCR), an auto-correlation function (ACF), and a covariance (COV) of a received signal, for estimating the maximum Doppler frequency.

10. A velocity estimation method for a communication system including a transmitter for transmitting at least one signal through at least one wireless channel and a receiver for receiving the at least one signal and restoring data, the method comprising the steps of:

detecting a pilot signal from a received signal;

band-limit filtering the pilot signal;

estimating a maximum Doppler frequency using the band-limit filtered pilot signal; and

generating velocity information using the estimated maximum Doppler frequency.

11. The method as claimed in claim 10, wherein a limit band for band-limit filtering is adaptively established based on a previously estimated maximum Doppler frequency.

12. The method as claimed in claim 10, wherein the limit band corresponds to {square root}{square root over ( 3/2)} times the previously estimated maximum Doppler frequency.

13. The method as claimed in claim 10, wherein the step for estimating a maximum Doppler frequency uses at least one of a zero-crossing-rate (ZCR), a level-crossing-rate (LCR), an auto-correlation function (ACF), and a covariance (COV) of a received signal, for estimating the maximum Doppler frequency.

14. A velocity estimation method for a mobile communication system including at least one base station for providing at least one mobile station within a service area with wireless access services, the method comprising the steps of:

down-converting a received wireless signal into a baseband signal;

outputting a digital signal by sampling a predetermined section of the baseband signal;

detecting a pilot signal from the digital signal;

band-limit filtering the pilot signal;

estimating a maximum Doppler frequency using the band-limit filtered pilot signal; and

converting the estimated maximum Doppler frequency into velocity information.

15. The method as claimed in claim 14, wherein a limit band for band-limit filtering is adaptively established based on a previously estimated maximum Doppler frequency.

16. The method as claimed in claim 15, wherein the limit band corresponds to {square root}{square root over ( 3/2)} times the previously estimated maximum Doppler frequency.

17. The method as claimed in claim 16, wherein the step for estimating a maximum Doppler frequency uses at least one of a zero-crossing-rate (ZCR), a level-crossing-rate (LCR), an auto-correlation function (ACF), and a covariance (COV) of a received signal, for estimating the maximum Doppler frequency.