System and method for adaptive equalization in a wireless communication system

• US 6,766,142 B2
• Filed: 01/23/2001
• Issued: 07/20/2004
• Est. Priority Date: 01/23/2001
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: King, Jay S.
• Primary Examiner(s): Trinh, Sonny
• Application Number:
  US09/767,443
• Publication Number:
  US 20020098805A1
• Time in Patent Office: 1,274 Days
• Field of Search: 455/522, 455/63, 455/39, 455/135, 455/67.13, 455/307, 455/213, 455/266, 455/340, 455/63.1, 455/222, 455/501, 455/570, 455/114.2, 455/283
• US Class Current: 455/63.1
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

A wireless communication device receives audio data from a base station via a radio frequency (RF) communication link (i.e., a forward link) and transmits audio data to the base station via the RF communication link (i.e., a reverse link). The wireless communication device uses the inherent functionality of the reverse link, including an audio input device (120) to determine whether the wireless communication device is operating in a high noise environment. A signal analyzer (124) analyzes the audio signal on the reverse link and determines whether the ambient noise level exceeds predetermined threshold. If so, the signal analyzer (124) activates a filter (126) to filter the audio signal being provided to an audio output transducer (122). Band limiting the audio signal provided to the audio output transducer (122) improves intelligibility of the audio signal in the presence of noise.

Claims

1. A system for adaptive equalization in a wireless communication system having a base station including a base station transmitter and a base station receiver, the base station transmitter transmitting audio data on a forward communication link, the base station receiver receiving audio data on a reverse communication link, the system comprising:

a mobile unit having a transmitter and a receiver to communicate with the base station the reverse and forward communication links, respectively;

a signal analyzer to analyze audio data to be transmitted on the reverse communication link and thereby determine a noise characteristic present at a location of the mobile unit, the signal analyzer generating signals indicative of the noise characteristic; and

a filter to filter spectral characteristics of the audio data received from the base station transmitter, the alter receiving the signals generated by the signal analyzer and altering the spectral characteristics of the audio data in response thereto, wherein the filter is a high-pass filter.

2. The system of claim 1, further comprising an output transducer, having a frequency response characteristic, to generate audible signals representative of the data received from the base station transmitter, a filter response characteristic being selected based on the frequency response characteristic of the output transducer.

3. The system of claim 1, further comprising a plurality of output transducers, each having a frequency response characteristic, one of which is selected generate audible signals representative of the data received from the base station transmitter, the filter response characteristic being adjustable and being selected based on the frequency response characteristic of the selected output transducer.

4. A system for adaptive equalization in a wireless communication device that transmits data to and receives data from a remote location, the system comprising:

a signal analyzer to analyze data to be transmitted to the remote location and determine therefrom a noise characteristic present at a location of the mobile unit, the signal analyzer generating signals indicative of the noise characteristic; and

an equalizer selectively activated by the generated signals to alter spectral characteristics of data received from the remote location in response thereto, wherein the equalizer comprises a high-pass filter.

5. The system of claim 4 wherein the signal analyzer periodically analyzes the data to be transmitted to the remote location and generates the signals indicative of the noise characteristic, the equalizer being an adaptive equalizer and periodically altering the spectral characteristics of the received data in response the signals periodically generated by the signal analyzer.

6. The system of claim 4, further comprising an output transducer, having a frequency response characteristic, to generate audible signals representative of the data received from the remote location, a high-pass filter response characteristic being selected based on the frequency response characteristic of the output transducer.

7. The system of claim 4, further comprising a plurality of output transducers, each having a frequency response characteristic, one of which is selected to generate audible signals representative of the data received from the remote location, the high-pass filter response characteristic being adjustable and being selected based on the frequency response characteristic of the selected output transducer.

8. A method for adaptive equalization in a wireless communication device transmits data to and receives data from a remote location, the method comprising:

analyzing data to be transmitted to the remote location and determining therefrom a noise characteristic present at a location of the mobile unit;

generating signals indicative of the noise characteristic; and

altering spectral characteristics of data received from the remote location in response to the generation of signals indicative of the noise characteristic, wherein a high-pass filter performs altering spectral characteristics of the data received from the remote location.

9. The method of claim 8 wherein the data to be transmitted to the remote location is periodically analyzed and the signals indicative of the noise characteristic periodically generated, the spectral characteristics of the received data being periodically altered in response the periodically generated signals indicative of the noise characteristic.

10. The method of claim 8 wherein altering spectral characteristics of the data received from the remote location comprises high-pass filtering of the data received from the remote location.

11. The method of claim 10 wherein the wireless communication device comprises an output transducer, having a frequency response characteristic, to generate audible signals representative of the data received from the remote location, the method further comprising selecting a high-pass filter response characteristic based on the frequency response characteristic of the output transducer.

12. The method of claim 10 wherein the wireless communication device comprises a plurality of output transducers, each having a frequency response characteristic, one of which is selected to generate audible signals representative of the data received from the remote location, the method further comprising altering spectral characteristics of data received from the remote location based on the frequency response characteristic of the selected output transducer.