| 摘要 |
The present invention provides apparatus and methods for position computation with high accuracy, low acquisition time and low power consumption. The position computation apparatus includes a radio communication receiver which monitors a radio communication network, such as a cellular network, covering the geographic region in which the position computation apparatus is located. The apparatus demodulates the signal from the radio communication network and obtains positioning data from the broadcast channel of the network for use in satellite acquisition operations prior to computing a position. The apparatus further includes a receiver for receiving positioning messages broadcast by a constellation of GPS satellites. A position computation circuit in the apparatus utilizes the positioning data obtained from the radio communication network in initial acquisition of one or more positioning satellites. Once the desired number of positioning satellites have been acquired, positioning messages are received from the acquired positioning satellites and used to calculate the position of the position computation apparatus.
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