| 摘要 |
For packet based data transmissions, a base station transmits an uplink status flag (USF) to a mobile station, which USF determines whether or not the mobile station may send data in one or more uplink timeslots. In the detection methods, a mobile node is assigned an USF and detects the presence of the USF in subsequent signal bursts transmitted to the mobile node. For the GPRS coding schemes CS2-CS4, the USF detection method comprises correlating the received USF samples with a plurality of possible USFs stored at the mobile node with the correlation weighted in favour of the assigned USF. False detection of the assigned USF can be minimised by checking the unscaled correlation value against a predetermined threshold. For the GPRS coding scheme CS1, for which there is no USF pre-coding, the received USF is decoded by the mobile node to provide an indication of decision confidence and the USF detection is rejected if the decision confidence is below a threshold. The path metric value is used to minimise false detection. |
