公开(公告)号：US20220224581A1

公开(公告)日：2022-07-14

申请号：US17613991

申请日：2020-05-27

Applicant: Kamstrup A/S

Inventor： Alex BIRKLYKKE ,  Mathias Rønholt KIELGAST

IPC: H04L27/26

Abstract: A method for detecting a constant envelope burst-mode radio frequency (RF) signal with a known periodic synchronization sequence (PSS) represented therein, e.g. to be for reading of data from utility meters. An incoming RF signal is transformed into a digital baseband signal (DBS), and the phase domain part is processed by: 1) applying a correlation algorithm to correlate the DBS with a synchronization pattern corresponding to the PSS. 2) filtering the resulting correlation signal for removing at least a DC component of the correlation signal. 3) down-sampling the filtered correlation signal (or the correlation signal) with a sampling time controlled by a clock aligned with amplitude peaks in the filtered correlation signal (or the correlation signal). 4) performing a decision algorithm on the down-sampled signal to determine if PSS is present in the incoming RF signal. Then, 5) generating an output signal indicating if the known PSS is present in the incoming RF signal, in response to a result of the decision algorithm. The steps 1)-5) serve to detect if an amplitude in the correlation signal indicates the presence of the known PSS. Preferably, a second decision algorithm serves to detect if periodicity in the correlation signal indicates the presence of the known PSS, and finally the results of the first and second decision algorithms can be combined, e.g. by a logic AND operation, to arrive at a sensitive and reliable PSS detection result.

公开(公告)号：US20240413964A1

公开(公告)日：2024-12-12

申请号：US18680218

申请日：2024-05-31

Applicant: Kamstrup A/S

Inventor： Alex BIRKLYKKE ,  Jesper Torsvik TOFT

IPC: H04L7/00 ,  H04Q9/00

Abstract: A radio communication method involves utility meters installed at distributed installation locations with a data receiver. Data is received from the utility meters. Data is modulated on a received signal having a time-varying phase offset. Decision-directed phase tracking compensates for the time-varying phase offset. The compensated received signal is coherently demodulated to extract data. Extracted data is modulated to reconstruct a replica of the received signal. A phase offset prediction error—comparison between compensated received signal and the replica—and a phase offset prediction error covariance-divergence of compensated received signal and reference value and/or of phase offset prediction error and error reference value—are estimated and input into a Kalman filter. A Kalman filter output provides a prediction of time-varying phase offset in a feedback loop to compensate time-varying phase offset of received signal before compensated received signal is coherently demodulated to extract data.