US6157820A
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US
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Pilot strength measurement and multipath delay searcher for CDMA receiver
Assignee: Ericsson Inc
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Filing: 1998-06-12
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Granted: 2000-12-05
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Expires: 2018-06-12
Abstract
Abstract A method and apparatus for evaluating signal strength of a channel received at a mobile station within a spread spectrum communication systems is disclosed. If the receiver at the mobile station receives a spread spectrum signal, a first sampling means converts the received signal into a first sample stream as a first sampling. A second sampling means converts the first sample stream into a second sample stream at a second sample rate, different from the first sample rate. The signal strength of a pilot channel is measured based upon the first and second sample streams.
Inventors
- 👤 Essam Abdelfattah Sourour
- 👤 Greg Bottomley
- 👤 Rajaram Ramesh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:02
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/76; H04B17/00; H04B17/30; H04B17/309; H04B17/318; H04B17/328; H04B1/69; H04B1/707; H04B1/7097; H04B1/711; H04B1/7115
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
89 words
A method for evaluating a channel's signal strength at a mobile station comprising the steps of: receiving a signal; converting the received signal into a first sample stream according to a first sampling rate; converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate; generating a search window for the first sample stream using a sliding correlator; and measuring the signal strength of the second sample stream using the search window.
Claim 2
Independent Claim
89 words
A method for evaluating a channel's signal strength at a mobile station comprising the steps of: receiving a signal; converting the received signal into a first sample stream according to a first sampling rate; converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate; generating a search window for the first sample stream using a sliding correlator; and measuring the signal strength of the second sample stream using the search window.
Claim 3
Dependent Claim
60 words
The method of claim 1, wherein the step of generating includes the steps of: feeding an arbitrary local section of the signal into a delay part of the sliding correlator; feeding a section of the received signal into a multiplying part of the sliding correlator; and multiplying the sections sequentially with each other to obtain a sequence of correlation values.
Claim 4
Dependent Claim
45 words
The method of claim 2, wherein the step of generating further comprises the steps of: averaging the search window using previously generated search windows for the pilot signal; and smoothing the generated samples of the search window with a smoothing factor using previously generated samples.
Claim 5
Dependent Claim
12 words
The method of claim 3, wherein the smoothing factor is approximately 0.96.
Claim 6
Dependent Claim
12 words
The method of claim 3, wherein the smoothing factor is approximately 0.99.
Claim 7
Dependent Claim
29 words
The method of claim 1, wherein the step of converting the received signal further comprises the step of: selecting an optimal down sampling phase for the second sample stream.
Claim 8
Dependent Claim
30 words
The method of claim 6, wherein the step of selecting comprises the step of: extracting the optimal down sampling phase from a tracking unit which has been tracking the signal.
Claim 9
Dependent Claim
26 words
The method of claim 6, wherein the step of selecting comprises the step of: selecting an arbitrary sampling phase which is changed sequentially for each measurement.
Claim 10
Dependent Claim
18 words
The method of claim 8, wherein the arbitrary sampling phase is changed sequentially over four consecutive sampling phases.
Claim 11
Dependent Claim
17 words
The method of claim 1, wherein the second sampling rate is lower than the first sampling rate.
Claim 12
Dependent Claim
31 words
The method of claim 1, wherein the step of converting the first sample stream comprises the step of: sampling the first sample stream at a rate of two samples per chip.
Claim 13
Independent Claim
106 words
An apparatus for evaluating CDMA channel signal strength at a mobile station in a spread spectrum communications system, comprising: a receiver for receiving a signal; first sampling means for converting the received signal into a first sample stream according to a first sampling rate; second sampling means for converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate; a sliding correlator for generating a search window for the first sample stream; and a measurer for measuring the signal strength of the second sample stream using the search window.
Claim 14
Independent Claim
106 words
An apparatus for evaluating CDMA channel signal strength at a mobile station in a spread spectrum communications system, comprising: a receiver for receiving a signal; first sampling means for converting the received signal into a first sample stream according to a first sampling rate; second sampling means for converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate; a sliding correlator for generating a search window for the first sample stream; and a measurer for measuring the signal strength of the second sample stream using the search window.
Claim 15
Independent Claim
102 words
A method for evaluating CDMA channel signal strength at a mobile station comprising the steps of: receiving a CDMA signal; converting the received CDMA signal into a first sample stream according to a first sampling rate; converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is lower than the first sampling rate; selecting an optimal down sampling phase for the second sample stream; generating a search window for the first sample stream using a sliding correlator; measuring the CDMA signal strength of the second sample stream using the search window.
Claim 16
Independent Claim
102 words
A method for evaluating CDMA channel signal strength at a mobile station comprising the steps of: receiving a CDMA signal; converting the received CDMA signal into a first sample stream according to a first sampling rate; converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is lower than the first sampling rate; selecting an optimal down sampling phase for the second sample stream; generating a search window for the first sample stream using a sliding correlator; measuring the CDMA signal strength of the second sample stream using the search window.
Claim 17
Dependent Claim
59 words
The method of claim 13, wherein the step of generating includes the steps of: feeding an arbitrary local section of the CDMA signal into a delay part of the sliding correlator; feeding the received CDMA signal into a multiplying part of the sliding correlator; and multiplying the sections sequentially with each other to obtain a sequence of correlated values.
Claim 18
Dependent Claim
24 words
The method of claim 14 further including the step of: centering a search window around the earliest detected correlation peak among the correlation values.
Claim 19
Dependent Claim
41 words
The method of claim 14, wherein the step of generating further comprises the steps of: averaging the search window using previously generated search windows for the CDMA signal; and smoothing the generated samples of the search window with a smoothing factor.
Claim 20
Dependent Claim
31 words
The method of claim 13, wherein the step of selecting comprises the step of: extracting the optimal down sampling phase from a tracking unit which has been tracking the CDMA signal.
Claim 21
Dependent Claim
26 words
The method of claim 13, wherein the step of selecting comprises the step of: selecting an arbitrary sampling phase which is changed sequentially for each measurement.
Claim 22
Dependent Claim
18 words
The method of claim 13, wherein the arbitrary sampling phase is changed sequentially over four consecutive sampling phases.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-12-05 | 2004-06-05 | 2004-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-05 | 2008-06-05 | 2008-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-05 | 2012-06-05 | 2012-12-05 | $7700.00 | Window Closed / Lapsed |