System and method for collection of transmission characteristics

DETAILED DESCRIPTION The present invention is embodied in a system and method for the collection of transmission characteristics for the authentication of a cellular telephone transmitter.
The system includes an enclosure sized to accept the cellular telephone.
A transmitter and receiver capable of operating at frequencies used for cellular telephone communication are included in the system.
An antenna is coupled to the transmitter and receiver and extends into the enclosure.
The antenna couples radio frequencies transmitted by the transmitter to the enclosure and receives radio signals emanating from the cellular telephone when in the enclosure and couples the received radio frequencies to the receiver.
The receiver generates receiver output signals representative of the received signals.
A processor is included to control the transmitter and cause the transmitter to transmit signals to the enclosure to elicit a transmission response signal from the cellular telephone when in the enclosure.
The processor also receives from the receiver output signals indicative of the transmission characteristic of the cellular telephone when in the enclosure and responding to the transmit signals from the transmitter.
In a preferred embodiment, the enclosure is substantially impenetrable to radio frequency signals.
The processor may selectively control operational parameters for the transmitter and receiver to control transmit signals during transmission to the cellular telephone in the enclosure and to control the receiver when receiving signals from the cellular telephone.
The operating parameters may include the selection of carrier frequency for the transmitter and receiver, and a selected transmission power level for the transmitter.
The receiver output signals indicative of the transmission characteristics may be processed by the processor to generate a fingerprint associated with the transmission characteristic.
The processor may store the fingerprint for subsequent use in the authentication of the cellular telephone when used outside of the enclosure