Radio signal detection
AssigneeNordic Semiconductor ASA
InventorJukka Tapaninen
Life of this patent
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Abstract
A radio receiver is provided for low-power detection of a radio signal, wherein said receiver is configured to receive a radio signal over a radio network; convert at least part of the received radio signal into a sequence of samples; compare the similarity of a first part of the sequence and a second part of the sequence, wherein the first part and the second part are of equal length; and in response to said similarity being greater than a similarity threshold: detect a phase difference between the first part of the sequence and the second part of the sequence; calculate a frequency offset between a frequency of the received radio signal and an expected frequency of the received radio signal using said phase difference; and use said calculated frequency offset to attempt full access to the radio network.
Claims22
A radio receiver configured to:
- receive a radio signal over a radio network;
- convert at least part of the received radio signal into a sequence of samples;
- compare a first part of the sequence and a second part of the sequence to determine a similarity, wherein the first part and the second part are of equal length;
- and
- in response to said similarity being greater than a similarity threshold;
- detect a phase difference between the first part of the sequence and the second part of the sequence;
- calculate a frequency offset between a frequency of the received radio signal and an expected frequency of the received radio signal using said phase difference;
- and
- use said calculated frequency offset to attempt full access to the radio network;
- and
- in response to the similarity being less than the similarity threshold, to check how much time has elapsed since an immediately previous attempt at full access;
- and
- if the elapsed time is greater than a time threshold, to attempt full access to the radio network.
A method of detection of a radio signal, said method comprising:
- receiving a radio signal over a radio network;
- converting at least part of the received radio signal into a sequence of samples;
- comparing a first part of the sequence and a second part of the sequence to determine a similarity, wherein the first part and the second part are of equal length;
- and
- in response to said similarity being greater than a similarity threshold:
- detecting a phase difference between the first part of the sequence and the second part of the sequence;
- calculating a frequency offset between a frequency of the received radio signal and an expected frequency of the received radio signal using said phase difference;
- and
- using said calculated frequency offset to attempt full access to the radio network;
- and
- in response to the similarity being less than the similarity threshold, checking how much time has elapsed since an immediately previous attempt at full access;
- and
- if the elapsed time is greater than a time threshold, attempting full access to the radio network.
Dependencies are inferred from the claim text.