Energy based communication rate detection system and method

• US 6,347,080 B2
• Filed: 09/09/1998
• Issued: 02/12/2002
• Est. Priority Date: 09/09/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Nicolas, Julien, Silberger, Amnon, Jou, Yu-Cheun
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/150,493
• Publication Number:
  US 20010019541A1
• Time in Patent Office: 1,252 Days
• Field of Search: 370/310, 370/252, 370/335, 370/331, 370/232, 370/342, 455/522, 455/422, 455/452, 375/200, 375/219, 375/335, 375/228, 375/316
• US Class Current: 370/310
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]

Abstract

A system and method for the detection of zero-rate communication frames on forward and reverse communication links is described herein. In a first embodiment, the rate determination process begins upon receiving pilot and traffic channel signals. The system then compares the received traffic channel energy with the pilot signal to obtain a metric. The metric is then compared with a predetermined threshold to detect the presence of a zero-rate traffic channel frame. In a second embodiment, the process begins with the receipt of a reverse communication link frame having first and second portions. The system then detects the energy contained in the first and second portions. The system compares the detected energy in the first portion with the detected energy in the second portion to obtain a metric. The system then compares the metric with a predetermined threshold to detect the presence of the zero-rate frame. The selection of the predetermined threshold in both embodiments is based on the probability of detection of a transmitted zero-rate frame and the probability of erroneously detecting a zero-rate frame.

Claims

1. A method for detecting a zero-rate traffic channel, comprising the steps of:

receiving a pilot channel frame and a traffic channel frame;

measuring an energy of said traffic channel frame;

measuring an energy of said pilot channel frame;

comparing said pilot channel frame energy to said traffic channel frame energy to obtain a metric by computing a ratio of said traffic channel frame energy to said pilot channel frame energy;

comparing said metric with a predetermined threshold to obtain a result by comparing the magnitude of said metric to the magnitude of said predetermined threshold, said predetermined threshold based on the probability of detection of a transmitted zero-rate traffic channel frame and the probability of erroneously detecting a zero-rate traffic channel frame; and

indicating whether a zero-rate traffic channel frame has been received based on said result.

2. The method of claim 1, wherein said indicating step comprises the step of indicating that a zero-rate traffic channel frame has been received when the magnitude of said predetermined threshold exceeds the magnitude of said metric.

3. A system for detecting a zero-rate traffic channel, comprising:

means for receiving a pilot channel frame and a traffic channel frame;

means for measuring an energy of said traffic channel frame;

means for measuring an energy of said pilot channel frame;

means for comparing said pilot channel frame energy to said traffic channel frame energy to obtain a metric, comprising means for computing a ratio of said traffic channel frame energy to said pilot channel frame energy;

means for comparing said metric with a predetermined threshold to obtain a result, comprising means for comparing the magnitude of said metric to the magnitude of said predetermined threshold, said predetermined threshold based on the probability of detection of a transmitted zero-rate traffic channel frame and the probability of erroneously detecting a zero-rate traffic channel frame; and

means for indicating whether a zero-rate traffic channel frame has been received based on said result.

4. The system of claim 3, wherein said means for indicating comprises means for indicating that a zero-rate traffic channel frame has been received when the magnitude of said predetermined threshold exceeds the magnitude of said metric.

5. A method for detecting a zero-rate traffic channel, comprising the steps of:

receiving a traffic channel frame having first and second portions;

measuring an energy of said first portion;

measuring an energy of said second portion;

comparing said energy of said first portion with said energy of said second portion to obtain a metric, comprising computing a weighted difference between said energy of said first portion said energy of said second portion;

comparing said metric with a predetermined threshold to obtain a result comprising the step of comparing said weighted difference to said predetermined threshold, said predetermined threshold based on the probability of detection of a transmitted zero-rate frame and the probability of erroneously detecting a zero-rate frame, to detect the presence of a zero-rate frame;

indicating whether a zero-rate traffic channel frame has been received based on said result.

6. The method of claim 5, wherein said indicating step comprises the step of:

indicating that a zero-rate traffic channel frame has been received when said weighted difference exceeds said predetermined threshold exceeds the magnitude of said metric.

7. A system for detecting a zero-rate traffic channel, comprising:

means for receiving a traffic channel frame having first and second portions;

means for measuring an energy of said first portion;

means for measuring an energy of said second portion;

means for comparing said energy of said first portion with said energy of said second portion to obtain a metric, comprising means for computing a weighted difference between said energy of said first portion said energy of said second portion;

means for comparing said metric with a predetermined threshold to obtain a result, comprising means for comparing said weighted difference to said predetermined threshold, said predetermined threshold based on the probability of detection of a transmitted zero-rate frame and the probability of erroneously detecting a zero-rate frame, to detect the presence of a zero-rate frame;

means for indicating whether a zero-rate traffic channel frame has been received based on said result.

8. The system of claim 7, wherein said means for indicating comprises means for indicating that a zero-rate traffic channel frame has been received when said weighted difference exceeds said predetermined threshold exceeds the magnitude of said metric.