Transmission of Information to a GPS Device
A terrestrial system for transmitting non-GPS information for reception by a global positioning system (GPS) receiver, the system including a processor, a memory coupled to the processor and including computer-readable instructions configured to, when executed by the processor, cause the processor to receive the non-GPS information, determine an available pseudo-random noise (PRN) code, spread the non-GPS information using the available PRN code to provide a spread signal, modulate a GPS carrier frequency using the spread signal to produce a GPS compatible signal, and a terrestrial transmitter configured to transmit the GPS compatible signal.
1 . A terrestrial system for transmitting non-GPS information for reception by a global positioning system (GPS) receiver, the system comprising:
a processor;
a memory coupled to the processor and including computer-readable instructions configured to, when executed by the processor, cause the processor to:
receive the non-GPS information;
determine an available pseudo-random noise (PRN) code;
spread the non-GPS information using the available PRN code to provide a spread signal;
modulate a GPS carrier frequency using the spread signal to produce a GPS compatible signal; and
a terrestrial transmitter configured to transmit the GPS compatible signal.
2 . The system of claim 1 wherein GPS carrier frequency is at least one of the L1, L2, and L5 carrier frequencies.
3 . The system of claim 1 wherein the terrestrial transmitter re-transmits existing GPS signals.
4 . The system of claim 1 wherein the transmitter is disposed within a building in a location where existing GPS signals cannot be received.
5 . The system of claim 1 wherein the non-GPS information includes E911 information.
6 . The system of claim 1 wherein the terrestrial transmitter is configured to transmit the GPS compatible signal using a duty cycle of substantially 10-30%.
7 . A terrestrial system for transmitting non-GPS information for reception by a global positioning system (GPS) receiver, the system comprising:
an input module configured to receive the non-GPS information;
a processor coupled to the input module, the processor being configured to determine an available pseudo-random noise (PRN) code and to produce a GPS compatible signal that is generated as a function of the available PRN code, the GPS compatible signal including a navigation message, the navigation message including the non-GPS information;
an amplifier coupled to the processor and configured to amplify the GPS compatible signal; and
a terrestrial transmitter coupled to the processor and configured to transmit the GPS compatible signal.
8 . The system of claim 7 wherein the non-GPS information is transmitted using a series of frames of consecutive navigation messages.
9 . The system of claim 7 where in the processor is configured to generate a plurality of GPS compatible signals, each generated as a function of a different available PRN code.
10 . The system of claim 7 wherein the terrestrial transmitter is configured to transmit the GPS compatible signal using a duty cycle of substantially 10-30%.
11 . A method of terrestrially transmitting non-GPS information for reception by a global positioning system (GPS) receiver, the method comprising:
receiving non-GPS information;
determining an available pseudo-random noise (PRN) code;
spreading the non-GPS information using the available PRN code to produce a spread signal;
modulating a GPS carrier frequency using the spread signal to produce a GPS compatible signal; and
transmitting the GPS compatible signal using a terrestrial transmitter.
12 . The method of claim 11 wherein transmitting the GPS compatible signal includes transmitting the GPS compatible signal using a duty cycle of substantially 10-30%.
13 . A system comprising:
a transmitter comprising:
a first processor configured to receive non-GPS information and to encode the non-GPS information in a navigation message of a global positioning system (GPS) signal to produce a GPS compatible signal, wherein an available pseudo-random noise (PRN) code is used to encode the non-GPS information;
a terrestrial transmitter configured to transmit the GPS compatible signal;
a GPS receiver comprising:
an antenna configured to receive GPS signals including the GPS compatible signal;
a second processor coupled to the antenna and configured to receive the GPS compatible signal from the antenna, the second processor being configured to recognize the presence of the non-GPS information in the GPS compatible signal and to process the GPS compatible signal in a predetermined manner.
14 . The system of claim 13 wherein the first processor is configured to encode the non-GPS information using an available pseudo-random noise (PRN) code.
15 . The system of claim 13 wherein the second processor is configured parse the navigation message to retrieve the non-GPS information.
16 . The system of claim 13 wherein the first processor is configured to produce a plurality of GPS compatible signals each encoded using a different available PRN code.
17 . The system of claim 16 wherein the second processor is configured to parse a plurality of GPS compatible signals according to the available PRN code used to encode the non-GPS information.
18 . The system of claim 16 wherein the non-GPS information is used by the receiver for providing location-based services.