SYSTEM AND METHOD FOR DETERMINATION OF POSITION
First Claim
1. A system for determining a position of a wireless device of a user, comprising:
- a plurality of wireless devices, said plurality of wireless devices including said wireless device of said user and one or more remote wireless devices, each of said one or more remote wireless devices being disposed at a determinable position,wherein each of said one or more remote wireless devices is operative to transmit at least one wireless signal comprising at least one code sequence, each of said at least one code sequence including a plurality of digital codes, andwherein said wireless device of said user is operative to receive said at least one wireless signal comprising said at least one code sequence transmitted by each of said one or more remote wireless devices, said wireless device of said user including at least one processor operative;
to correlate said plurality of digital codes in each code sequence with a reference code to determine a peak correlation time for each of said plurality of digital codes in the respective code sequence;
to filter the peak correlation times for said plurality of digital codes in each code sequence; and
to perform, using the filtered peak correlation times for said plurality of digital codes in each code sequence, a time-of-arrival (TOA) calculation for the respective code sequence, the TOA calculations for the respective code sequences being used to determine said position of said wireless device of said user.
0 Assignments
0 Petitions
Accused Products
Abstract
A system and method of determining and reporting on the position of a wireless device relative to a group of other wireless devices dispersed within a specified geographic area. The system includes at least one Query Unit, three or more Responding Units disposed at determinable locations within the specified geographic area, and one or more Mobile Units, which may correspond to additional Responding Units or units that function only as receivers. The Query Unit sequentially queries the Responding Units, and, responsive to the respective query messages, the Responding Units transmit corresponding response messages. One or more of the Mobile Units receive the query and response messages, and generate, for each query-response message pair, a set of time-difference-of-arrival (TDOA) measurements, which are used by the Mobile Units to determine their positions relative to the Responding Units. The Mobile Units record the times-of-arrival (TOAs) of the query message and the response messages at their respective receivers, and calculate the TDOAs based on the recorded TOAs. The TDOAs are then analyzed to determine the time differences due to the differences in lengths of the respective message propagation paths. The position of each Mobile Unit can then be computed using computation techniques typically employed in Long Range Navigation (LORAN) receivers, or any other suitable computation technique.
-
Citations
40 Claims
-
1. A system for determining a position of a wireless device of a user, comprising:
-
a plurality of wireless devices, said plurality of wireless devices including said wireless device of said user and one or more remote wireless devices, each of said one or more remote wireless devices being disposed at a determinable position, wherein each of said one or more remote wireless devices is operative to transmit at least one wireless signal comprising at least one code sequence, each of said at least one code sequence including a plurality of digital codes, and wherein said wireless device of said user is operative to receive said at least one wireless signal comprising said at least one code sequence transmitted by each of said one or more remote wireless devices, said wireless device of said user including at least one processor operative; to correlate said plurality of digital codes in each code sequence with a reference code to determine a peak correlation time for each of said plurality of digital codes in the respective code sequence; to filter the peak correlation times for said plurality of digital codes in each code sequence; and to perform, using the filtered peak correlation times for said plurality of digital codes in each code sequence, a time-of-arrival (TOA) calculation for the respective code sequence, the TOA calculations for the respective code sequences being used to determine said position of said wireless device of said user. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. A method of determining a position of a wireless device of a user, comprising the steps of:
-
providing a plurality of wireless devices, said plurality of wireless devices including said wireless device of said user and one or more remote wireless devices, each of said one or more remote wireless devices being disposed at a determinable position, said wireless device of said user including at least one processor; in a first transmitting step, transmitting, by each of said one or more remote wireless devices, at least one wireless signal comprising at least one code sequence, each of said at least one code sequence including a plurality of digital codes; receiving, by said wireless device of said user, said at least one wireless signal comprising said at least one code sequence transmitted by each of said one or more remote wireless devices; correlating, by said at least one processor included in said wireless device of said user, said plurality of digital codes in each code sequence with a reference code to determine a peak correlation time for each of said plurality of digital codes in the respective code sequence; filtering, by said at least one processor included in said wireless device of said user, the peak correlation times for said plurality of digital codes in each code sequence; and in a performing step, performing, by said at least one processor included in said wireless device of said user using the filtered peak correlation times for said plurality of digital codes in each code sequence, a time-of-arrival (TOA) calculation for the respective code sequence, the TOA calculations for the respective code sequences being used to determine said position of said wireless device of said user. - View Dependent Claims (34, 35, 36, 37, 38)
-
-
39. In a system for performing wireless ranging measurements, a method of automatic gain control (AGC) of an output signal generated from a wireless input signal, the output signal having an associated gain, said system including at least one wireless device having at least one processor and an AGC stage for controlling the gain of the output signal in accordance with a gain control (GN) value, said at least one processor including a buffer, the GN value having an associated incremental (Δ
- G) value, the Δ
G value having an associated sign, said method comprising the steps of;in a generating step, generating, from the output signal, at least one quadrature-phase (Q) signal, the Q signal having an associated magnitude (|Q|) value; in an accumulating step, accumulating the |Q| value of the Q signal in said buffer; in a first repeating step, repeating said generating step and said accumulating step until a specified number of |Q| values are accumulated in said buffer; in a calculating step, in the event said specified number of |Q| values of the Q signal are accumulated in said buffer, calculating a variance (σ
N) of the |Q| values accumulated in said buffer;in a reversing step, in the event the calculated variance σ
N is greater than a previous variance (σ
N-1), reversing the sign of the Δ
G value;in an adding step, adding the Δ
G value to a previous gain control (GN-1) value to obtain the GN value; andin a controlling step, controlling, by said AGC stage, the gain of the output signal in accordance with the GN value to obtain a gain-controlled output signal. - View Dependent Claims (40)
- G) value, the Δ
Specification