
US Patent No: 5,841,768
Number of patents in Portfolio can not be more than 2000
Method of controlling initial power ramp-up in CDMA systems by using short codes
Stats
-
Nov 24, 1998
Issued date -
Jun 27, 1996
filing date -
08/670,162
serial no -
In Force
status
Importance
Abstract
A system and method of controlling transmission power during the establishment of a channel in a CDMA communication system utilize the transmission of a short code from a subscriber unit to a base station during initial power ramp-up. The short code is a sequence for detection by the base station which has a much shorter period than a conventional spreading code. The ramp-up starts from a power level that is guaranteed to be lower than the required power level for detection by the base station. The subscriber unit quickly increases transmission power while repeatedly transmitting the short code until the signal is detected by the base station. Once the base station detects the short code, it sends an indication to the subscriber unit to cease increasing transmission power. The use of short codes limits power overshoot and interference to other subscriber stations and permits the base station to quickly synchronize to the spreading code used by the subscriber unit.
First Claim
Related Publications
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
|
|
|||
| 5,056,109 Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system | 809 | 1989 | |
| 5,265,119 Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system | 383 | 1991 | |
| 5,257,283 Spread spectrum transmitter power control method and system | 288 | 1991 | |
| 5,267,262 Transmitter power control system | 417 | 1991 | |
| 5,309,474 System and method for generating signal waveforms in a CDMA cellular telephone system | 293 | 1992 | |
| 5,414,728 Method and apparatus for bifurcating signal transmission over in-phase and quadrature phase spread spectrum communication channels | 225 | 1993 | |
|
|
|||
| 5,353,352 Multiple access coding for radio communications | 138 | 1992 | |
| 5,430,760 Random access in mobile radio telephone systems | 180 | 1994 | |
| 5,377,183 Calling channel in CDMA communications system | 121 | 1994 | |
|
|
|||
| 5,159,283 Power amplifier | 67 | 1991 | |
| 5,235,614 Method and apparatus for accommodating a variable number of communication channels in a spread spectrum communication system | 102 | 1992 | |
|
|
|||
| 5,327,455 Method and device for multiplexing data signals | 189 | 1993 | |
|
|
|||
| 5,353,302 Signal despreader for CDMA systems | 78 | 1993 | |
|
|
|||
| 5,442,662 Code-division multiple-access communication system providing enhanced capacity within limited bandwidth | 125 | 1994 | |
|
|
|||
| 5,446,756 Integrated cellular communications system | 314 | 1993 | |
|
|
|||
| 5,113,525 Linear-modulation type radio transmitter | 60 | 1990 | |
|
|
|||
| 5,297,162 System and method for bit timing synchronization in an adaptive direct sequence CDMA communication system | 106 | 1993 | |
|
|
|||
| 5,022,049 Multiple access code acquisition system | 90 | 1989 | |
|
|
|||
| 4,811,421 Transmission power control device in a radio communication transmitting/receiving station | 189 | 1987 | |