Mobile device locator

An apparatus comprising:

• a fingerprint locator to estimate a first position of a mobile device based on received signal strengths of communications signals in comparison to received signal strengths of a fingerprint database, wherein the first position is estimated based on a discrete probability distribution of the received signal strengths of communication signals;
• a sensor analyzer to measure movement of the mobile device;
• a particle allocator to control particles of a particle filter based on the first position of the mobile device and movement of the mobile device, wherein the particle allocator is further to:
• assign weights to the particles, the weights corresponding to distance between the first position and the respective particles;
• resample the particles by removing a number of particles having weights that satisfy a first weight threshold and adding the same number of new particles to new sampling coordinates within a threshold distance of particles having weights that satisfy a second weight threshold, the resampling including application of a respective random drift to at least some of the particles, wherein a random drift applied to at least one first particle among the particles is different from a random drift applied to at least one second particle among the particles;
• a movement analyzer to analyze movement of the mobile device until a threshold period of time has elapsed since the mobile device has moved and a position of the mobile device has been estimated a threshold number of times;
• and
• a position calculator to estimate a second position of the mobile device based on sampling coordinates of the particles.

A non-transitory machine readable storage medium comprising instructions that, when executed, cause a machine to at least:

• estimate a first position of a mobile device by comparing received signal strength indications of communication signals to received signal strength indications of a fingerprint database, wherein the first position is estimated based on a discrete probability distribution of the received signal strength indications of communication signals;
• allocate particles to sampling locations within a threshold distance of the first position, the particles comprising respective weights, wherein allocating particles further comprises:
• determining the weights of the respective particles based on the distance between the first position and the respective particles;
• and
• removing a portion of the particles based on the weights of the particles of the portion of the particles failing to satisfy a weight threshold;
• analyze movement of the mobile device based on inertial measurements from sensors of the mobile device;
• move the particles to new sampling locations in accordance with the movement of the mobile device, the moving including application of a respective random drift to at least some of the particles, wherein a random drift applied to at least one first particle among the particles is different from a random drift applied to at least one second particle among the particles;
• determine to cease analyzing movement of the mobile device, the determining further comprising:
• determine that a threshold period of time has elapsed since the mobile device has moved;
• and
• determine that a position of the mobile device has been estimated a threshold number of times;
• and
• calculate a new position of the mobile device based on the new sampling locations.