Initial power control for spread-spectrum communications
First Claim
1. A method of using a code division multiple access (CDMA) system including at least one base station in communication with a plurality of subscriber units, the method comprising:
- (a) the base station transmitting a synchronization channel having a code signal used for synchronization by the plurality of subscriber units;
(b) a first one of the subscriber units receiving and acquiring the synchronization channel;
(c) the first subscriber unit synchronizing to the synchronization channel;
(d) the first subscriber unit determining timing from the synchronization channel;
(e) the first subscriber unit transmitting an access signal having a plurality of power levels;
(f) the base station detecting the access signal and, in response, transmitting an acknowledgement signal to the first subscriber unit; and
(g) the first subscriber unit receiving the acknowledgment signal and, in response, transmitting a spread-spectrum signal with data to the base station.
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Abstract
A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.
161 Citations
10 Claims
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1. A method of using a code division multiple access (CDMA) system including at least one base station in communication with a plurality of subscriber units, the method comprising:
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(a) the base station transmitting a synchronization channel having a code signal used for synchronization by the plurality of subscriber units;
(b) a first one of the subscriber units receiving and acquiring the synchronization channel;
(c) the first subscriber unit synchronizing to the synchronization channel;
(d) the first subscriber unit determining timing from the synchronization channel;
(e) the first subscriber unit transmitting an access signal having a plurality of power levels;
(f) the base station detecting the access signal and, in response, transmitting an acknowledgement signal to the first subscriber unit; and
(g) the first subscriber unit receiving the acknowledgment signal and, in response, transmitting a spread-spectrum signal with data to the base station. - View Dependent Claims (2)
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3. A code division multiple access (CDMA) system comprising:
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(a) at least one base station; and
(b) a plurality of subscriber units in communication with the base station, wherein;
(i) the base station transmits a synchronization channel having a code signal used for synchronization by the plurality of subscriber units;
(ii) a first one of the subscriber units receives and acquires the synchronization channel;
(iii) the first subscriber unit synchronizes to the synchronization channel;
(iv) the first subscriber unit determines timing from the synchronization channel;
(v) the first subscriber unit transmits an access signal having a plurality of power levels;
(vi) the base station detects the access signal and, in response, transmits an acknowledgement signal to the first subscriber unit; and
(vii) the first subscriber unit receives the acknowledgment signal and, in response, transmits a spread-spectrum signal with data to the base station. - View Dependent Claims (4)
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5. A method of using a code division multiple access (CDMA) system including at least one base station in communication with a plurality of subscriber units, the method comprising:
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(a) the base station transmitting a synchronization channel having a code signal used for synchronization by the plurality of subscriber units;
(b) a first one of the subscriber units synchronizing to the synchronization channel and determining timing from the synchronization channel;
(c) the first subscriber unit transmitting an access signal based on the timing determined in step (b);
(d) the base station detecting the access signal and, in response, transmitting an acknowledgement signal to the first subscriber unit; and
(e) the first subscriber unit receiving the acknowledgment signal and, in response, transmitting a spread-spectrum signal with data to the base station. - View Dependent Claims (6)
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7. A code division multiple access (CDMA) system comprising:
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(a) at least one base station; and
(b) a plurality of subscriber units in communication with the base station, wherein;
(i) the base station transmits a synchronization channel having a code signal used for synchronization by the plurality of subscriber units;
(ii) a first one of the subscriber units synchronizes to the synchronization channel and determines timing from the synchronization channel;
(iii) the first subscriber unit transmits an access signal based on the timing determined by the first subscriber unit;
(iv) the base station detects the access signal and, in response, transmits an acknowledgement signal to the first subscriber unit; and
(v) the first subscriber unit receives the acknowledgment signal and, in response, transmits a spread-spectrum signal with data to the base station. - View Dependent Claims (8)
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9. A code-division-multiple-access (CDMA) system comprising:
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(a) means for transmitting, using spread-spectrum modulation, a synchronization channel having a code signal used for synchronization;
(b) means for receiving the synchronization channel;
(c) means for determining timing from the synchronization channel;
(d) means for transmitting, using spread-spectrum modulation, an access signal, the access signal having a plurality of power levels;
(e) means for detecting the access signal;
(f) means for transmitting an acknowledgment signal in response to detecting the access signal;
(g) means for receiving the acknowledgment signal; and
(h) means for transmitting a spread-spectrum signal with data in response to receiving the acknowledgment signal. - View Dependent Claims (10)
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Specification