Systems and methods for device localization

A playback device comprising:

• one or more amplifiers configured to drive one or more speakers;
• one or more processors;
• data storage having stored therein instructions executable by the one or more processors to cause the playback device to perform a method comprising:
• obtaining characteristics of signals transmitted via signal paths between each of a plurality of reference playback devices in a media playback system over a period of time;
• obtaining characteristics of signals transmitted via signal paths between a portable device and each of the plurality of reference playback devices;
• normalizing the obtained characteristics to estimate characteristics of the signal paths between each of the plurality of reference playback devices and between the portable device and each of the plurality of reference playback devices, wherein normalizing the measured characteristics of signals transmitted between a first reference device and a second reference device comprises computing a weighted average of at least one characteristic for a first set of one or more signals from the first reference device to the second reference device and a second set of one or more signals from the second reference device to the first reference device;
• estimating a likelihood that the portable device is in a particular location using the estimated characteristics of the signal paths between each of the plurality of reference playback devices and the estimated characteristics of the signal paths between the portable device and each of the plurality of reference playback devices;
• identifying a ranked listing of a plurality of target reference playback devices of the plurality of reference playback devices based on the estimated likelihood;
• and
• transmitting the ranked listing of target reference playback devices to the portable device, wherein the portable device modifies a user interface at the portable device based on the ranked listing.

A controller device, the controller device comprising:

• a display configured to display a graphical user interface;
• one or more processors;
• and
• data storage having stored therein instructions executable by the one or more processors to cause the controller device to perform a method comprising:
• obtaining characteristics of signals transmitted via signal paths between each of a plurality of reference playback devices in a media playback system over a period of time;
• obtaining characteristics of signals transmitted via signal paths between the controller device and each of the plurality of reference playback devices;
• normalizing the obtained characteristics to estimate characteristics of the signal paths between each of the plurality of reference playback devices and between the controller device and each of the reference playback devices, wherein normalizing the obtained characteristics of signals transmitted between a first reference device and a second reference device comprises computing a weighted average of at least one characteristic for a first set of one or more signals from the first reference device to the second reference device and a second set of one or more signals from the second reference device to the first reference device;
• estimating the likelihood that the controller device is in a particular location using the estimated characteristics of the signal paths between each of the plurality of reference playback devices and the estimated characteristics of the signal paths between the controller device and each of the plurality of reference playback devices;
• identifying a set of one or more target reference playback devices of the plurality of reference playback devices based on the estimated likelihood;
• and
• modifying the graphical user interface displayed on the display based on the identified set of target reference playback devices.