DEVICES, METHODS, AND APPARATUSES FOR MOBILE DEVICE ACQUISITION ASSISTANCE
Methods, apparatuses and/or articles of manufacture, which may be employed in a mobile device and/or in a location server, enable acquisition assistance at the mobile device. In at least one implementation, which is not intended to limit claimed subject matter, acquisition assistance may include expected Doppler frequency shift and expected code phase in the case of a particular Global Navigation Satellite System (GNSS) satellite vehicle, as well as a search window for each of these, and a confidence value. The confidence value may indicate the likelihood of detecting signals from the satellite vehicle at the current expected location of the mobile device and within the given search windows and may enable one or more of faster location estimation, reduced battery consumption, and detection of weaker satellite signals.
1 . A method at a mobile device, comprising:
receiving one or more acquisition assistance parameters for use in acquisition of one or more positioning system signals defining at least one search window and a confidence value;
attempting acquisition of at least one of said positioning system signals by searching in a range defined by said at least one search window; and
extending said at least one search window in response to an absence of detection of at least one characteristic of said one or more positioning system signals in said range based, at least in part, on said confidence value.
2 . The method of claim 1 , additionally comprising:
receiving a reliability indicator pertaining to said confidence value.
3 . The method of claim 1 , wherein said at least one search window comprises a GNSS Doppler frequency shift and a GNSS pseudorandom code phase for signals transmitted from a satellite positioning system (SPS).
4 . The method of claim 3 , wherein said at least one search window comprises at least a portion of a GNSS Doppler frequency shift from −5.0 kHz to +5.0 kHz from a carrier frequency.
5 . The method of claim 3 , wherein said at least one search window comprises a GNSS pseudorandom code phase of between 0.0 and 1.0 ms.
6 . The method of claim 1 , further comprising:
transmitting an estimated position to a location server after acquiring at least one signal from a satellite positioning system (SPS).
7 . The method of claim 1 , wherein said at least one search window comprises a range of timing values for measuring time difference of arrival or pilot phase at said mobile device.
8 . An apparatus comprising:
a first receiver to receive satellite positioning system (SPS) signals;
a second receiver to receive messages transmitted in a wireless communication network; and
one or more processors configured to:
obtain one or more acquisition assistance parameters defining at least one search window and a confidence value from one or more messages received from said second receiver;
extend said at least one search window in response to an absence of detection of at least one characteristic of said SPS signals received from in a range based, at least in part, on said confidence value.
9 . The apparatus of claim 8 , further comprising a transmitter, and wherein the one or more processors are further configured to transmit a position estimate through the transmitter obtained based, at least in part, on acquisition of said SPS signals at said first receiver.
10 . The apparatus of claim 8 , wherein the one or more processors are further configured to determine said confidence value based, at least in part, on a reliability indicator obtained from messages received at the second receiver.
11 . The apparatus of claim 8 , wherein said at least one search window comprises a GNSS Doppler frequency shift and a GNSS pseudorandom code phase for signals transmitted from a satellite positioning system (SPS).
12 . The apparatus of claim 11 , wherein said at least one search window comprises at least a portion of a GNSS Doppler frequency shift from −5.0 kHz to +5.0 kHz from a carrier frequency.
13 . The apparatus of claim 11 , wherein said at least one search window comprises a GNSS pseudorandom code phase of between 0.0 and 1.0 ms.
14 . The apparatus of claim 8 , wherein said at least one search window comprises a range of timing values for measuring time difference of arrival or pilot phase at said apparatus.
15 . An article comprising:
a storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to:
obtain one or more acquisition assistance parameters for use in acquisition of one or more positioning system signals and a confidence value, said acquisition assistance parameters defining a range within at least one search window; and
extend said at least one search window in response to an absence of detection of at least one characteristic of a received positioning system signals in said range based, at least in part, on said confidence value.
16 . The article of claim 15 , wherein said one or more positioning system signals are transmitted from at least one space vehicle of a satellite positioning system (SPS).
17 . The article of claim 15 , wherein said one or more positioning system signals are transmitted from at least one terrestrial base station.
18 . The article of claim 15 , wherein the instructions are further executable by the special purpose computing apparatus to initiate transmission of a position estimate obtained based, at least in part, on acquisition of said SPS signals at a first receiver.
19 . The article of claim 15 , wherein the instructions are further executable by the special purpose computing apparatus to determine said confidence value based, at least in part, on a reliability indicator obtained from messages received at a second receiver.
20 . The article of claim 15 , wherein said at least one search window comprises a GNSS Doppler frequency shift and a GNSS pseudorandom code phase for signals transmitted from a satellite positioning system (SPS).
21 . The article of claim 20 , wherein said at least one search window comprises at least a portion of a GNSS Doppler frequency shift from −5.0 kHz to +5.0 kHz from a carrier frequency.
22 . The article of claim 20 , wherein said at least one search window comprises a GNSS pseudorandom code phase of between 0.0 and 1.0 ms.
23 . The article of claim 15 , wherein said at least one search window comprises a range of timing values for measuring time difference of arrival or pilot phase at a mobile device.
24 . An apparatus comprising:
means for receiving one or more acquisition assistance parameters for use in acquisition of one or more positioning system signals defining at least one search window and a confidence value;
means for attempting acquisition of at least one positioning system signals by searching in a range defined by said at least one search window; and
means for extending said at least one search window in response to an absence of detection of at least one characteristic of said one or more positioning system signals in said range based, at least in part, on said confidence value.
25 . The apparatus of claim 24 , additionally comprising:
means for receiving a reliability indicator pertaining to said confidence value.
26 . The apparatus of claim 24 , wherein said at least one search window comprises a GNSS Doppler frequency shift and a GNSS pseudorandom code phase for signals transmitted from a satellite positioning system (SPS).
27 . The apparatus of claim 26 , wherein said at least one search window comprises at least a portion of a GNSS Doppler frequency shift from −5.0 kHz to +5.0 kHz from a carrier frequency.
28 . The apparatus of claim 24 , further comprising:
means for transmitting an estimated position to a location server after acquiring at least one signal from a satellite positioning system (SPS).
29 . The apparatus of claim 24 , wherein said at least one search window comprises a range of timing values for measuring time difference of arrival or pilot phase at said apparatus.