Collision detection
First Claim
1. An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) with a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations, with each remote station (RS) having an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver, the method comprising the steps of:
- transmitting from said BS-spread-spectrum transmitter located at said base station, a broadcast common-synchronization channel having a common chip-sequence signal common to the plurality of remote stations, the broadcast common-synchronization channel having a frame-timing signal;
receiving at a first RS-spread-spectrum receiver the broadcast common-synchronization channel, and determining frame timing at said first RS-spread-spectrum receiver from the frame-timing signal;
transmitting from a first RS-spread-spectrum transmitter an access-burst signal, the access-burst signal having a collision-detection portion;
receiving at said BS spread-spectrum receiver the access-burst signal, including the collision-detection portion;
transmitting from said BS-spread-spectrum transmitter to said first RS-spread-spectrum receiver, responsive to receiving the access-burst signal with the collision-detection portion, a collision-detection signal, the collision-detection signal including the collision-detection portion from the access-burst signal;
receiving at said first RS-spread-spectrum receiver the collision-detection signal with the collision detection portion; and
transmitting from said first RS-spread-spectrum transmitter, responsive to receiving the collision-detection signal, to said BS-spread-spectrum receiver, a spread-spectrum signal having data.
2 Assignments
0 Petitions
Accused Products
Abstract
An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal. The access-burst signal includes a collision-detection portion. In response to the BS-spread-spectrum receiver receiving the access-burst signal, the BS-spread-spectrum transmitter transmits an collision-detection signal with the collision detection portion. In response to the BS-spread-spectrum receiver not receiving the access-burst signal due to a collision with a collision access-burst signal, the BS-spread-spectrum transmitter transmits an collision-detection signal without the correct collision detection portion.
-
Citations
2 Claims
-
1. An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) with a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations, with each remote station (RS) having an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver, the method comprising the steps of:
-
transmitting from said BS-spread-spectrum transmitter located at said base station, a broadcast common-synchronization channel having a common chip-sequence signal common to the plurality of remote stations, the broadcast common-synchronization channel having a frame-timing signal;
receiving at a first RS-spread-spectrum receiver the broadcast common-synchronization channel, and determining frame timing at said first RS-spread-spectrum receiver from the frame-timing signal;
transmitting from a first RS-spread-spectrum transmitter an access-burst signal, the access-burst signal having a collision-detection portion;
receiving at said BS spread-spectrum receiver the access-burst signal, including the collision-detection portion;
transmitting from said BS-spread-spectrum transmitter to said first RS-spread-spectrum receiver, responsive to receiving the access-burst signal with the collision-detection portion, a collision-detection signal, the collision-detection signal including the collision-detection portion from the access-burst signal;
receiving at said first RS-spread-spectrum receiver the collision-detection signal with the collision detection portion; and
transmitting from said first RS-spread-spectrum transmitter, responsive to receiving the collision-detection signal, to said BS-spread-spectrum receiver, a spread-spectrum signal having data.
-
-
2-4. -4. (canceled)
Specification