US6208873B1
Expired / Lapsed
US
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Method and apparatus for transmitting reverse link power control signals based on the probability that the power control command is in error
Assignee: Qualcomm Inc
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Filing: 1998-11-23
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Granted: 2001-03-27
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Expires: 2018-11-23
Abstract
Abstract A method and apparatus for controlling the transmit power of a plurality of mobile radio units transmitting to a base station in a mobile radio telephone system. For each of the mobile units in the system, a signal strength estimate is measured at the base station based on reverse link signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units. The signal strength estimate associated with each mobile unit is compared to a threshold. Next, for each mobile unit in the plurality of mobile units, if the signal strength estimate associated with the mobile unit is greater than the threshold, then a power control bit having a first value is assigned to the mobile unit; conversely, if the signal strength estimate associated with the mobile unit is less than the threshold, then a power control bit having a second value is assigned to the mobile unit. A variable gain that is a function of the difference between the signal strength estimate associated with the mobile unit and the threshold is next applied to each power control bit. The variable gain applied to each power control bit increases as the magnitude of the difference between the signal strength estimate associated with the mobile unit and the threshold increases. Each gain-adjusted power control bit is then transmitted to the mobile units.
Inventors
- 👤 Peter J. Black
- 👤 Eduardo A. S. Esteves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:16
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04W; H04W52/00; H04W52/04; H04W52/18; H04W52/06; H04W52/10; H04W52/54; H04W52/56
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
104 words
A method for controlling the transmit power allocated to an information signal transmitted from a first site within a communication system, the method comprising the steps of: (A) assessing a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site; (B) applying a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; and (C) after step (B), transmitting the information signal from the first site.
Claim 2
Independent Claim
104 words
A method for controlling the transmit power allocated to an information signal transmitted from a first site within a communication system, the method comprising the steps of: (A) assessing a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site; (B) applying a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; and (C) after step (B), transmitting the information signal from the first site.
Claim 3
Dependent Claim
43 words
The method of claim 1 , wherein step (B) further comprises selecting a value of the variable gain from a set of candidate variable gain values, the set of candidate variable gain values including at least two different non-zero candidate variable gain values.
Claim 4
Dependent Claim
28 words
The method of claim 2 , wherein the set of candidate variable gain values includes a zero gain value that corresponds to an erasure of the information signal.
Claim 5
Dependent Claim
51 words
The method of claim 1 , wherein the first site is a base station in a mobile radio communication system having a plurality of mobile units and the information signal is a power control bit transmitted from the base station for controlling the reverse link transmit power of a mobile unit.
Claim 6
Dependent Claim
264 words
The method of claim 4 , wherein the step of assessing a probability further comprises the steps of: (A) measuring, at the base station, at least one signal strength estimate associated with each of the mobile unit, each measurement based on reverse link signals sent from the associated mobile unit and received at the base station and comparing the signal strength estimate associated with each mobile unit to a threshold; and wherein the step of applying the variable gain further comprises the steps of: (B) for each mobile unit in the plurality of mobile units: (i) assigning a power control bit having a first value to the mobile unit and applying a variable gain to the power control bit if the signal strength estimate associated with the mobile unit is greater than the threshold; and (ii) assigning a power control bit having a second value to the mobile unit and applying a variable gain to the power control bit if the signal strength estimate associated with the mobile unit is less than the threshold; (iii) wherein the variable gain applied in steps (i) and (ii) to each power control bit is a function of a difference between the signal strength estimate associated with the mobile unit and the threshold, and wherein the variable gain applied to the power control bit in steps (i) and (ii) increases as the difference between the signal strength estimate associated with the mobile unit and the threshold increases; and (C) wherein the step of transmitting the information signal further comprises transmitting each power control bit to the mobile units.
Claim 7
Dependent Claim
100 words
The method of claim 5 , wherein the variable gain applied in steps (i) and (ii) to each power control bit corresponds to a first gain value when a magnitude of the difference between the signal strength estimate associated with the mobile unit and the threshold is less than a first positive amount, and the variable gain applied in steps (i) and (ii) to each power control bit corresponds to a second gain value when the magnitude of the difference between the signal strength estimate associated with the mobile unit and the threshold is more than the first positive amount.
Claim 8
Dependent Claim
25 words
The method of claim 6 , wherein the first gain value corresponds to an erasure and the second gain value corresponds to a positive gain.
Claim 9
Dependent Claim
71 words
The method of claim 6 , wherein the variable gain applied in steps (i) and (ii) to each power control bit corresponds to a third gain value when the magnitude of the difference between the signal strength estimate associated with the mobile unit and the threshold is greater than the first positive amount and less than a second positive amount, the second positive amount being greater than the first positive amount.
Claim 10
Dependent Claim
74 words
The method of claim 5 , further comprising the step of providing a plurality of power control channels for transmitting power control information from the base station to the mobile units, each of the power control channels being assigned to one of the plurality of mobile units and using one of a plurality of different orthogonal codes for transmitting the power control bits from the base station to a mobile unit in step (C).
Claim 11
Dependent Claim
46 words
The method of claim 9 , wherein step (C) comprises simultaneously transmitting each power control bit to the mobile units during a time interval, wherein each power control bit is transmitted to the mobile units on a different one of the plurality of power control channels.
Claim 12
Dependent Claim
106 words
The method of claim 10 , wherein transmission from said base station of said first value of said power control bit on a first power control channel represents a command to a first mobile unit to increase the transmit power of signals sent from the first mobile unit to the base station on the reverse link, and transmission from said base station of said second value of said power control bit on a second power control channel represents a command to a second mobile unit to decrease the transmit power of signals sent from the second mobile unit to the base station on the reverse link.
Claim 13
Dependent Claim
24 words
The method of claim 5 , wherein steps (A)-(C) are performed repeatedly during successive time slots for each of the plurality of mobile units.
Claim 14
Dependent Claim
54 words
The method of claim 5 , wherein step (A) further comprises, for each of the mobile units, measuring at the base station, a signal strength estimate based on pilot signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units.
Claim 15
Dependent Claim
122 words
The method of claim 5 , further comprising the steps of: (A) determining a received power control signal value at a mobile station by demodulating transmissions on the power control channel associated with the mobile station; (B) comparing the received power control signal value to second and third thresholds at the mobile station; (C) if the received power control bit value is greater than the second threshold, then increasing the transmit power of signals sent from the mobile unit to the base station on the reverse link; and (D) if the received power control bit value is less than the third threshold, then decreasing the transmit power of signals sent from the mobile unit to the base station on the reverse link.
Claim 16
Dependent Claim
16 words
The method of claim 14 , wherein the second threshold is equal to the third threshold.
Claim 17
Dependent Claim
16 words
The method of claim 14 , wherein the second threshold is greater than the third threshold.
Claim 18
Dependent Claim
52 words
The method of claim 16 , further comprising the step of: (A) if the received power control signal value is less than the second threshold and greater than the third threshold, then holding constant the transmit power of signals sent from the mobile unit to the base station on the reverse link.
Claim 19
Dependent Claim
267 words
The method of claim 1 , wherein the first site is a base station in a mobile radio communication system having a plurality of mobile units, the second site is one of the plurality of mobile units, and step (A) further comprises the steps of: (A) for each of the mobile units, measuring at the base station, a signal strength estimate based on reverse link signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units, and comparing the signal strength estimate associated with each mobile unit to a high threshold and a low threshold; step (B) further comprises the steps of: (B) for each mobile unit in the plurality of mobile units: (i) if the signal strength estimate associated with the mobile unit is greater than the high threshold, then assigning a power control bit having a first value to the mobile unit; and (ii) if the signal strength estimate associated with the mobile unit is less than the low threshold, then assigning a power control bit having a second value to the mobile unit; and (iii) if the signal strength estimate associated with the mobile unit is less than the high threshold and greater than the low threshold, then associating a power control bit erasure with the mobile unit; and step (C) further comprises: (C) transmitting each power control bit having the first and second value to the mobile units, wherein transmission of a power control bit is inhibited for each mobile unit having a power control bit erasure associated therewith.
Claim 20
Dependent Claim
117 words
The method of claim 18 , further comprising the step of providing a plurality of power control channels for transmitting power control information from the base station to the mobile units, each of the power control channels being assigned to one of the plurality of mobile units and using one of a plurality of different orthogonal codes for transmitting power control information from the base station to a mobile unit, wherein step (B)(iii) comprises the step of: (iii) if the signal strength estimate associated with the mobile unit is less than the high threshold and greater than the low threshold, then associating a power control bit erasure with the power control channel assigned to the mobile unit.
Claim 21
Dependent Claim
88 words
The method of claim 19 , wherein step (C) further comprises simultaneously transmitting each power control bit having the first and second value to the mobile units during a time interval, wherein each power control bit having the first value or the second value is transmitted to the mobile units on a different one of the plurality of power control channels, and wherein transmission of a power control bit is inhibited during the time interval for each power control channel having a power control bit erasure associated therewith.
Claim 22
Dependent Claim
106 words
The method of claim 20 , wherein transmission from said base station of said first value of said power control bit on a first power control channel represents a command to a first mobile unit to increase the transmit power of signals sent from the first mobile unit to the base station on the reverse link, and transmission from said base station of said second value of said power control bit on a second power control channel represents a command to a second mobile unit to decrease the transmit power of signals sent from the second mobile unit to the base station on the reverse link.
Claim 23
Dependent Claim
24 words
The method of claim 21 , wherein steps (A)-(C) are performed repeatedly during successive time slots for each of the plurality of mobile units.
Claim 24
Dependent Claim
54 words
The method of claim 18 , wherein step (A) comprises: (A) for each of the mobile units, measuring at the base station, a signal strength estimate based on pilot signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units.
Claim 25
Dependent Claim
20 words
The method of claim 18 , wherein the power control bits transmitted in step (C) are transmitted using BPSK modulation.
Claim 26
Dependent Claim
32 words
The method of claim 18 , further comprising the steps of setting the high threshold above a desired signal strength value and setting the low threshold below the desired signal strength value.
Claim 27
Dependent Claim
34 words
The method of claim 25 , wherein the high threshold is set k db above the desired signal strength value and the low threshold is set k db below the desired signal strength value.
Claim 28
Dependent Claim
122 words
The method of claim 20 , further comprising the steps of: (A) determining a received power control signal value at a mobile station by demodulating transmissions on the power control channel associated with the mobile station; (B) comparing the received power control signal value to third and fourth thresholds at the mobile station; (C) if the received power control bit value is greater than the third threshold, then increasing the transmit power of signals sent from the mobile unit to the base station on the reverse link; and (D) if the received power control bit value is less than the fourth threshold, then decreasing the transmit power of signals sent from the mobile unit to the base station on the reverse link.
Claim 29
Dependent Claim
16 words
The method of claim 27 , wherein the third threshold is equal to the fourth threshold.
Claim 30
Dependent Claim
16 words
The method of claim 27 , wherein the third threshold is greater than the fourth threshold.
Claim 31
Dependent Claim
52 words
The method of claim 29 , further comprising the step of: (A) if the received power control bit value is less than the third threshold and greater than the fourth threshold, then holding constant the transmit power of signals sent from the mobile unit to the base station on the reverse link.
Claim 32
Dependent Claim
124 words
In a communication system having a first site that transmits an information signal to a second site, an apparatus for controlling the transmit power allocated to the information signal at the first site, comprising: (A) a controller that assesses a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site to the second site; (B) an amplifier that applies a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; (C) a transmitter that transmits the information signal from the first site to the second site.
Claim 33
Dependent Claim
124 words
In a communication system having a first site that transmits an information signal to a second site, an apparatus for controlling the transmit power allocated to the information signal at the first site, comprising: (A) a controller that assesses a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site to the second site; (B) an amplifier that applies a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; (C) a transmitter that transmits the information signal from the first site to the second site.
Claim 34
Dependent Claim
41 words
The apparatus of claim 31 , wherein the controller selects a value of the variable gain from a set of candidate variable gain values, the set of candidate variable gain values including at least two different non-zero candidate variable gain values.
Claim 35
Dependent Claim
28 words
The apparatus of claim 32 , wherein the set of candidate variable gain values includes a zero gain value that corresponds to an erasure of the information signal.
Claim 36
Dependent Claim
62 words
The apparatus of claim 31 , wherein the first site is a base station in a mobile radio communication system having a plurality of mobile units, the second site is one of the plurality of mobile units, and the information signal is a power control bit transmitted from the base station for controlling the reverse link transmit power of a mobile unit.
Claim 37
Dependent Claim
224 words
The apparatus of claim 34 , wherein the controller calculates, for each of the mobile units, a signal strength estimate based on reverse link signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units; the controller compares the signal strength estimate associated with each mobile unit to a threshold; and, for each mobile unit in the plurality of mobile units, the controller assigns a power control bit having a first value to the mobile unit if the signal strength estimate associated with the mobile unit is greater than the threshold, and the controller assigns a power control bit having a second value to the mobile unit if the signal strength estimate associated with the mobile unit is less than the threshold; wherein the amplifier applies the variable gain to each power control bit, the variable gain applied by the amplifier to each power control bit being a function of a difference between the signal strength estimate associated with the mobile unit and the threshold such that the variable gain applied by the amplifier to each power control bit increases as the difference between the signal strength estimate associated with the mobile unit and the threshold increases; and wherein the transmitter transmits each power control bit to the mobile units.
Claim 38
Dependent Claim
60 words
The apparatus of claim 35 , wherein the transmitter transmits the power control bits on a plurality of power control channels, each of the power control channels being assigned to one of the plurality of mobile units and using one of a plurality of different orthogonal codes for transmitting power control information from the base station to a mobile unit.
Claim 39
Dependent Claim
46 words
The apparatus of claim 36 , wherein the transmitter simultaneously transmits each power control bit to the mobile units during a time interval such that each power control bit is transmitted to the mobile units on a different one of the plurality of power control channels.
Claim 40
Dependent Claim
121 words
In a communication system having a first site that transmits an information signal to a second site, an apparatus for controlling the transmit power allocated to the information signal at the first site, comprising: (A) means for assessing a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site to the second site; (B) means for applying a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; (C) means for transmitting the information signal from the first site to the second site.
Claim 41
Dependent Claim
121 words
In a communication system having a first site that transmits an information signal to a second site, an apparatus for controlling the transmit power allocated to the information signal at the first site, comprising: (A) means for assessing a probability that the information signal contains erroneous information prior to transmission of the information signal from the first site to the second site; (B) means for applying a variable gain to the information signal in accordance with the probability that the information signal contains erroneous information, wherein the variable gain applied to the information signal decreases as the probability that the information signal contains erroneous information increases; (C) means for transmitting the information signal from the first site to the second site.
Claim 42
Dependent Claim
43 words
The apparatus of claim 38 , wherein the means for assessing selects a value of the variable gain from a set of candidate variable gain values, the set of candidate variable gain values including at least two different non-zero candidate variable gain values.
Claim 43
Dependent Claim
28 words
The apparatus of claim 39 , wherein the set of candidate variable gain values includes a zero gain value that corresponds to an erasure of the information signal.
Claim 44
Dependent Claim
62 words
The apparatus of claim 38 , wherein the first site is a base station in a mobile radio communication system having a plurality of mobile units, the second site is one of the plurality of mobile units, and the information signal is a power control bit transmitted from the base station for controlling the reverse link transmit power of a mobile unit.
Claim 45
Dependent Claim
207 words
The apparatus of claim 41 , wherein the means for assessing comprises means for measuring, for each of the mobile units, a signal strength estimate based on reverse link signals sent from the mobile units and received at the base station, wherein each signal strength estimate is associated with one of the mobile units; and means for comparing the signal strength estimate associated with each mobile unit to a threshold; the apparatus further comprising means for assigning a power control bit having a first value to each mobile unit having an associated signal strength estimate that is greater than the threshold, and means for assigning a power control bit having a second value to each mobile unit having an associated signal strength estimate that is less than the threshold; wherein the variable gain applied to each power control bit by the means for applying is a function of a difference between the signal strength estimate associated with the mobile unit and the threshold, and wherein the variable gain applied to each power control bit increases as the difference between the signal strength estimate associated with the mobile unit and the threshold increases; and wherein the means for transmitting transmits each power control bit to the mobile units.
Claim 46
Dependent Claim
62 words
The apparatus of claim 42 , wherein the means for transmitting transmits the power control bits on a plurality of power control channels, each of the power control channels being assigned to one of the plurality of mobile units and using one of a plurality of different orthogonal codes for transmitting power control information from the base station to a mobile unit.
Claim 47
Dependent Claim
48 words
The apparatus of claim 43 , wherein the means for transmitting simultaneously transmits each power control bit to the mobile units during a time interval such that each power control bit is transmitted to the mobile units on a different one of the plurality of power control channels.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-03-26 | 2004-09-25 | 2005-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-26 | 2008-09-25 | 2009-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-26 | 2012-09-25 | 2013-03-27 | $7700.00 | Window Closed / Lapsed |