Patent ID: 11943713
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Digital communication (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A method of operating a wireless device operative in a wireless communication network, comprising a primary receiver circuit and a low-power wakeup receiver, the method comprising:
suspending operation of the primary receiver circuit to conserve power;
operating the low-power wakeup receiver circuit;
receiving one or more wakeup signals transmitted by the network;
down-converting the one or more wakeup signals using an uncalibrated local oscillator signal;
demodulating and decoding the down-converted one or more wakeup signals;
extracting frequency related information from the decoded one or more wakeup signals;
using the extracted frequency related information to correct the local oscillator signal frequency;
receiving subsequent wakeup signals transmitted by the network in a frequency hopping pattern, wherein each wakeup signal includes information related to the frequency location of a subsequent wakeup signal;
using the frequency-corrected local oscillator signal to down-convert subsequent wakeup signals transmitted by the network;
performing narrowband filtering on the down-converted, subsequent wakeup signals and
demodulating and decoding the filtered, down-converted, subsequent wakeup signals.