Method and apparatus for locating mobile multimedia multicast system capable wireless devices

A program storage device readable by computer, tangibly embodying a program of instructions executable by said computer to perform an operation of estimating a current location of a receiver in a mobile multimedia multicast system comprising said receiver, at least three transmitters, and a wireless network, said operation comprising:

• receiving digital signals comprising a mobile multimedia multicast system superframe comprising orthogonal frequency division multiplexing (OFDM) symbols;
• performing slot 3 processing of each medium access control (MAC) time unit of a data channel to identify a transmitter identity (TxID) of each transmitter;
• identifying corresponding geographical coordinates of each TxID;
• regenerating said digital signals for each of said transmitters using a local-area differentiator (LID) and a wide-area differentiator (WID) of said transmitters;
• dividing said digital signals received from said transmitters by the corresponding regenerated transmitted signal to obtain channel estimates between said receiver and the corresponding transmitters;
• detecting a first peak in said channel estimates to determine a distance between said receiver and said corresponding transmitters, wherein the detecting comprises:
• measuring a noise level at slot 5 of said MAC time unit;
• measuring a signal level of the remaining slots of said MAC time unit;
• obtaining a level of the signal-to-noise ratio (SNR) of said digital signals;
• and
• setting a threshold level to detect each peak in said channel estimates;
• calculating a time difference of arrival of said digital signals emitted from said transmitters;
• and
• estimating a current location of said receiver by determining said time difference of arrival associated with geographical coordinates of said receiver.

An apparatus for estimating a current location of a wireless device in a mobile multimedia multicast system comprising at least three transmitters in a wireless network, said apparatus comprising:

• a receiver that receives digital signals comprising a mobile multimedia multicast system superframe comprising orthogonal frequency division multiplexing (OFDM) symbols;
• and
• a processor that:
• performs slot 3 processing of each medium access control (MAC) time unit of a data channel to identify a transmitter identity (TxID) of each transmitter;
• identifies corresponding geographical coordinates of each TxID;
• regenerates said digital signals for each of said transmitters using a local-area differentiator (LID) and a wide-area differentiator (WID) of said transmitters;
• divides said digital signals received from said transmitters by the corresponding regenerated transmitted signal to obtain channel estimates between said receiver and the corresponding transmitters;
• detects a first peak in said channel estimates to determine a distance between said receiver and said corresponding transmitters, wherein the detecting comprises:
• measuring a noise level at slot 5 of said MAC time unit;
• measuring a signal level of the remaining slots of said MAC time unit;
• obtaining a level of the signal-to-noise ratio (SNR) of said digital signals;
• and
• setting a threshold level to detect each peak in said channel estimates;
• calculates a time difference of arrival of said digital signals emitted from said transmitters;
• and
• estimates a current location of said receiver by determining said time difference of arrival associated with geographical coordinates of said receiver.