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US 12,356,330 B2Granted
Fast wakeup recovery for NBIOT systems
AssigneeSTMicroelectronics International N.V.
InventorsAbdelmohsen Ali, Mohammed Ashraf, Elsayed Ahmed
Life of this patent
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Abstract
Systems, apparatuses, methods, and computer products for fast wakeup recovery for narrow-band internet of things (NBIOT) systems are provided. The fast wakeup recovery may wakeup a NBIOT device from a sleep mode to an active mode. The fast wakeup recovery may identify a servicing cell for the NBIOT device to synchronize with. The fast wakeup recovery may be based on a coarse timing detection operation using a NPSS and a fine timing detection operation using a NSSS.
Claims18
A method comprising:
- executing a wakeup recovery operation, wherein the wakeup recovery operation comprises:
- executing, by an NBIOT modem of a NBIOT device, a coarse timing detection operation, wherein the coarse timing detection operation generates a coarse timing offset and a coarse frequency offset based on a sampled signal by:
- generating, via a downsampler, a downsampled signal based on the sampled signal;
- determining a plurality of frequency offsets;
- generating a plurality of offset downsampled signals based on the plurality of frequency offsets and the downsampled signal, wherein each of the plurality of offset downsampled signals has a different frequency offset;
- correlating the offset downsampled signals with a plurality of NPSS matched filters, wherein each of the NPSS matched filters is based on an NPSS sequence and one of the plurality of offset downsampled signals;
- approximating an absolute value of each of the plurality of correlated offset downsampled signals;
- averaging each of the plurality of approximated absolute values of each of the correlated offset downsampled signals;
- dynamically scaling each of the plurality of averaged approximated absolute values of each of the correlated offset downsampled signals;
- determining a coarse timing maximum of the plurality of dynamically scaled averaged approximated absolute values of each of the correlated offset downsampled signals;
- determining the coarse timing offset and the coarse frequency offset based on the coarse timing maximum;
- executing, by the NBIOT modem, a fine timing detection operation, wherein a fine timing sample operation generates a cell identifier based on the sampled signal, the coarse timing offset, and the coarse frequency offset;
- and
- entering, by the NBIOT device, an active mode wherein the NBIOT modem is synchronized with a cell associated with the cell identifier.
11 more elements
A NBIOT device comprising:
- an NBIOT modem, wherein the NBIOT modem is configured to:
- execute a wakeup recovery operation, wherein the wakeup recovery operation comprises:
- execute a coarse timing detection operation, wherein the coarse timing detection operation generates a coarse timing offset and a coarse frequency offset based on a sampled signal by:
- generate, via a downsampler, a downsampled signal based on the sampled signal;
- determine a plurality of frequency offsets;
- generate a plurality of offset downsampled signals based on the plurality of frequency offsets and the downsampled signal, wherein each of the plurality of offset downsampled signals has a different frequency offset;
- correlate the offset downsampled signals with a plurality of NPSS matched filters, wherein each of the NPSS matched filters is based on an NPSS sequence and one of the plurality of offset downsampled signals;
- approximate an absolute value of each of the plurality of correlated offset downsampled signals;
- average each of the plurality of approximated absolute values of each of the correlated offset downsampled signals;
- dynamically scale each of the plurality of averaged approximated absolute values of each of the correlated offset downsampled signals;
- determine a coarse timing maximum of the plurality of dynamically scaled averaged approximated absolute values of each of the correlated offset downsampled signals;
- and
- determine the coarse timing offset and the coarse frequency offset based on the coarse timing maximum;
- execute a fine timing detection operation, wherein a fine timing sample operation generates a cell identifier based on the sampled signal, the coarse timing offset, and the coarse frequency offset;
- and
- enter an active mode wherein the NBIOT modem is synchronized with a cell associated with the cell identifier.
13 more elements
A modem comprising at least one processor and at least one memory coupled to the processor, wherein the processor is configured to:
- execute a wakeup recovery operation, wherein the wakeup recovery operation comprises:
- execute a coarse timing detection operation, wherein the coarse timing detection operation generates a coarse timing offset and a coarse frequency offset based on a sampled signal by:
- generate, via a downsampler, a downsampled signal based on the sampled signal;
- determine a plurality of frequency offsets;
- generate a plurality of offset downsampled signals based on the plurality of frequency offsets and the downsampled signal, wherein each of the plurality of offset downsampled signals has a different frequency offset;
- correlate the offset downsampled signals with a plurality of NPSS matched filters, wherein each of the NPSS matched filters is based on an NPSS sequence and one of the plurality of offset downsampled signals;
- approximate an absolute value of each of the plurality of correlated offset downsampled signals;
- average each of the plurality of approximated absolute values of each of the correlated offset downsampled signals;
- dynamically scale each of the plurality of averaged approximated absolute values of each of the correlated offset downsampled signals;
- determine a coarse timing maximum of the plurality of dynamically scaled averaged approximated absolute values of each of the correlated offset downsampled signals;
- and
- determine the coarse timing offset and the coarse frequency offset based on the coarse timing maximum;
- execute a fine timing detection operation, wherein a fine timing sample operation generates a cell identifier based on the sampled signal, the coarse timing offset, and the coarse frequency offset;
- and
- enter an active mode wherein the modem is synchronized with a cell associated with the cell identifier.
12 more elements
Dependencies are inferred from the claim text.