Patent EA-004523-B1 (EA)
Title: Common packet channel
Inventor: KANTERAKIS EMMANUEL
IPC: H04J13/00
Filed: 2000-03-21
Abstract: 1. A method in a code-division-multiple-access (CDMA) system employing spread spectrum modulation comprising a base station (BS) comprising a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations, each remote station (RS) comprising an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver, a method comprising the steps of: transmitting from said BS-spread-spectrum transmitter, a broadcast common synchronization channel having a common chip-sequence signal common to the plurality of remote stations, the broadcast common-synchronization channel comprising a frame-timing signal; receiving at an RS-spread-spectrum receiver of one remote station the broadcast common-synchronization channel, and determining frame timing at said RS-spread-spectrum receiver from the frame-timing signal; transmitting from an RS-spread-spectrum transmitter of the one remote station an access-burst signal, the access-burst signal comprising a plurality of segments having a plurality of respective power levels; receiving at said BS spread-spectrum receiver at least one segment of the access-burst signal at a detected-power level; responsive to receipt of the at least one segment, transmitting an acknowledgment signal from said BS-spread-spectrum transmitter; receiving the acknowledgment signal at said RS-spread-spectrum receiver; transmitting, from said RS-spread-spectrum transmitter, responsive to receipt of the acknowledgment signal, a selected RS-collision-detection (CD) preamble from a plurality of RS-CD preambles; detecting, at said BS-spread-spectrum receiver, the selected RS-CD preamble; transmitting, from said BS-spread-spectrum transmitter in response to detecting the selected RS-CD preamble, a BS-CD preamble corresponding to the selected RSCD preamble; detecting, at said RS-spread-spectrum receiver, the BS-CD preamble; transmitting from said RS-spread-spectrum transmitter, responsive to the receipt of the BS-CD preamble, a spread-spectrum signal comprising data; and transmitting from said BS-spread-spectrum transmitter, any of data and power control information, to said RS-spread-spectrum receiver. 2. A method as set forth in claim1, wherein the step of transmitting the access-burst signal comprises transmitting the plurality of segments at sequentially increasing power levels. 3. An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, the CDMA system comprising a base station (BS) and a plurality of remote stations (RS), the improvement comprising: a BS spread-spectrum transmitter located at said base station, for transmitting a broadcast common-synchronization channel having a common chip-sequence signal, the broadcast common-synchronization channel comprising a frame-timing signal; an RS-spread-spectrum receiver, located at one of the remote stations, for receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal; an RS-spread-spectrum transmitter, located the one first remote station, for transmitting an access-burst signal, the access-burst signal comprising a plurality of segments having a plurality of respective power levels; a BS spread-spectrum receiver at said base station for receiving at least one segment of the access-burst signal at a detected-power level; said BS-spread-spectrum transmitter for transmitting an acknowledgment signal responsive to receiving the at least one segment; said RS-spread-spectrum receiver for receiving the acknowledgment signal; said RS-spread-spectrum transmitter transmits a selected RS-collision-detection (CD) preamble from a plurality of RS-CD preambles, in response to receipt of the acknowledgment signal; said BS-spread-spectrum receiver detects the selected RS-CD preamble; said BS-spread-spectrum transmitter transmits a BS-CD corresponding to the received RS-CD preamble; said RS-spread-spectrum receiver detects the BS-CD preamble; said RS-spread-spectrum transmitter for transmitting a spread-spectrum signal comprising data, responsive to the receipt of the BS-CD preamble; and said BS-spread-spectrum transmitter for transmitting any of data and power control information, to said RS-spread-spectrum receiver. 4. The improvement as set forth in claim 3, wherein said RS-spread-spectrum transmitter transmitting the access-burst signal transmits the segments at sequentially increasing power levels. 5. A method in a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, the CDMA system comprising a first base station (BS) comprising a first BS-spread-spectrum transmitter and a first BS-spread-spectrum receiver, a second base station comprising a second BS-spread-spectrum transmitter and a second BS spread-spectrum receiver, and a plurality of remote stations, each remote station (RS) comprising an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver, a method comprising the steps of: transmitting from said first BS-spread-spectrum transmitter a first broadcast common-synchronization channel having a first common chip-sequence signal common to the plurality of remote stations, the first broadcast common-synchronization channel comprising a first frame-timing signal; transmitting from said second BS-spread-spectrum transmitter, a second broadcast common-synchronization channel having a second common chip-sequence signal, the second broadcast common-synchronization channel comprising a second frame-timing signal; at one remote station, receiving in the RS-spread-spectrum receiver the first broadcast common-synchronization channel, and determining a first frame timing from the first frame-timing signal; receiving at the RS-spread-spectrum receiver of the one remote station the second broadcast common-synchronization channel, and determining a second frame timing from the second frame-timing signal; responsive to the received common-synchronization channels, determining, based on any of power levels and probabilities of error, at said one remote station to transmit to said first base station; from the RS-spread-spectrum transmitter of the one remote station, transmitting a first access-burst signal, the first access-burst signal comprising a first plurality of at a first plurality of respective power levels; receiving at said first BS spread-spectrum receiver at least one segment of the first access-burst signal at a first detected-power level; transmitting from said first BS-spread-spectrum transmitter a first acknowledgment signal, responsive to the receipt of the at least one segment; transmitting, from the RS-spread-spectrum transmitter of the one remote station an RS-collision-detection (CD) preamble selected from a plurality of RS-CD preambles, responsive to receipt of the first acknowledgment signal; detecting, at said first BS-spread-spectrum receiver, the selected RS-CD preamble; transmitting a first BS-CD preamble from said first BS-spread-spectrum transmitter corresponding to the detected RS-CD preamble; detecting, at the RS-spread-spectrum receiver of the one remote station, the first BS-CD preamble; responsive to the receipt of the first BS-CD preamble, transmitting a first spread-spectrum signal comprising data from the RS-spread-spectrum transmitter of the one remote station; and transmitting from said first BS-spread-spectrum transmitter, any of data and power-control information, to the RS-spread-spectrum receiver of the one remote station. 6. The method as set forth in claim 5, further comprising the step of transmitting from said first BS-spread-spectrum transmitter, any of data and power-control information, to the RS-spread-spectrum receiver of the one remote station. 7. The method as set forth in claim 5, further comprising the steps of: determining, based on any of power levels and probabilities of error, at the one remote station, from the first and the second broadcast common-synchronization channels, to further transmit to said second base station; transmitting from the RS-spread-spectrum transmitter of the one remote station to said second base station, a second access-burst signal comprising a second plurality of segments at a second plurality of respective power levels; receiving at said second BS-spread-spectrum receiver at least one segment of the second access-burst signal at a second detected-power level; transmitting a second acknowledgment signal from said second BS-spread-spectrum transmitter, responsive to the receipt of the at least one segment of the second access-burst signal; transmitting, from the RS-spread-spectrum transmitter of the one remote station an RS-collision-detection (CD) preamble selected from a plurality of RS-CD preambles, responsive to receipt of the second acknowledgment signal; detecting, at said second BS-spread-spectrum receiver, the selected RS-CD preamble; transmitting a second BS-CD preamble from said second BS-spread-spectrum transmitter corresponding to the detected RS-CD preamble; detecting, at the RS-spread-spectrum receiver of the one remote station, the second BS-CD preamble; transmitting a second spread-spectrum signal comprising data from said RS-spread-spectrum transmitter of the one remote station, responsive to the receipt of the second BS-CD preamble to said second BS-spread-spectrum receiver; and transmitting from said second BS-spread-spectrum transmitter, any of data and power-control information, to the RS-spread-spectrum receiver of the one remote station. 8. The method as set forth in claim 7, further comprising the step of transmitting from said second BS-spread-spectrum transmitter, any of data and power-control information, to the RS-spread-spectrum receiver of the one remote station. 9. An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, the CDMA system comprising a first base station (BS), a second base station, and a plurality of remote stations (RS) with each rem