Patent ID: 11906648
Assignee: HERE GLOBAL B.V.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 5:
6. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
apply a frequency transform to a set of radio data to obtain transform coefficients, the set of radio data comprising signal strength related values that are associated with a representation of a geographical location, each transform coefficient comprising a transform index and an associated transform value;
based upon energy of frequency transformed radio data, select at least a minimum number of transform indices having more significant transform values than the remaining transform indices; and
encode selected transform indices exploiting a probability of occurrence of an index value of a respective transform index,
wherein the apparatus is caused to select at least the minimum number of transform indices by excluding the transform coefficient corresponding to a direct current (DC) component.