公开(公告)号：US11784709B2

公开(公告)日：2023-10-10

申请号：US17919187

申请日：2021-04-15

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Lyonel Barthe ,  Benjamin Gadat

IPC: H04B7/185

CPC classification number: H04B7/18513

Abstract: A method and a receiver device for detecting the start of a frame of a satellite communication signal. A shaping filtering is applied directly after sampling of the signal, before a frequency correction is applied. During a first phase, an approximate frequency error and a candidate first sample for the start of the frame are estimated by performing several correlations respectively associated with different frequency hypotheses. The samples obtained after sampling or after shaping filtering are buffered during the execution of the first phase. Then, during a second phase, a final candidate sample for the start of the frame is determined from the memorised samples, using the approximate frequency error and the candidate first sample estimated during the first phase.

公开(公告)号：US11463157B2

公开(公告)日：2022-10-04

申请号：US17618736

申请日：2020-06-10

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Thibault Maisonnat ,  Benjamin Gadat

IPC: H04B7/185 ,  H04L7/00 ,  H04L1/00

Abstract: A method for receiving an ADS-B message is disclosed including a synchronisation phase for detecting the start of the message and a decoding phase for recovering a bit stream corresponding to a block of data in the message. The synchronisation phase is based on determining a sequence of log-likelihood ratios having the greatest likelihood of corresponding to a sequence of symbols expected from a preamble of the message. Each log-likelihood ratio corresponds to a ratio between the respective probabilities that a symbol of the signal received corresponds to one of two possible values for a symbol. The decoding phase applies a belief propagation algorithm to a sequence of log-likelihood ratios respectively associated with the symbols in the block of data in the message, with an optimised parity matrix of the cyclic redundancy code of the message.

公开(公告)号：US11909416B2

公开(公告)日：2024-02-20

申请号：US18018224

申请日：2021-07-19

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Benjamin Gadat ,  Lyonel Barthe

IPC: H03M13/00 ,  H03M13/11

CPC classification number: H03M13/116 ,  H03M13/611

Abstract: A data encoding device suitable for encoding a plurality of LDPC codes is disclosed including an input interface and an output interface, and a first circuit for encoding quasi-cyclic LDPC code, connected at an input to the input interface and at an output to the input of a first multiplexer circuit, a second circuit for encoding quasi-cyclic LDPC code, connected at an input to the input interface and at an output to the input of the first multiplexer circuit, a third circuit for encoding quasi-cyclic LDPC code, connected at an input to the output of the first multiplexer circuit and at an output to the input of a second multiplexer circuit.

公开(公告)号：US11005691B2

公开(公告)日：2021-05-11

申请号：US16759238

申请日：2018-10-22

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Benjamin Gadat ,  Mehdi Anteur

IPC: H04L27/00 ,  G01R23/02 ,  H04B7/185

Abstract: A method (50) for estimating a frequency shift and a frequency drift affecting a useful signal including a code word formed by a channel encoder, including an analysis phase (51) including: for two analysis frequency drifts: a compensation (52) of the analysis frequency drift on the useful signal, an estimation (53) of the frequency shift on each useful signal obtained after compensation, a selection (54) of frequency hypotheses,
and an estimation phase (55) including: for each frequency hypothesis: a frequency recalibration (56) of the useful signal depending on the frequency hypothesis, in order to obtain sample sequences, an evaluation (57) of the probability of each sample sequence to be a code word of said channel encoder, an estimation (58) of the frequency shift and of the frequency drift depending on the most probable frequency hypothesis.

公开(公告)号：US11032817B2

公开(公告)日：2021-06-08

申请号：US16336299

申请日：2017-09-29

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Benjamin Gadat ,  Vincent Deslandes

IPC: H04W72/04 ,  H04B1/713 ,  H04L1/00 ,  H04W4/70 ,  H04W4/06 ,  H04W74/08 ,  H04W4/80 ,  H04B7/185 ,  H04J13/00 ,  H04B1/715 ,  H04J11/00 ,  H04L1/04

Abstract: A method for transmitting, by a terminal, a message destined for a receiver station of a wireless communication system. The message being transmitted on a shared channel on which the transmission of messages is performed at the start of predetermined time intervals, termed slots. Data to be included in the message to be transmitted is encoded. The encoded data is distributed between Nb sub-messages of the message to be transmitted, Nb being an integer number greater than or equal to two. A slot is selected for transmitting the message. Nb transmission frequencies are selected, each respectively associated with the Nb sub-messages of the message. The message is transmitted at the start of the selected slot, by successively transmitting the sub-messages on their respective associated transmission frequencies.

公开(公告)号：US10554291B2

公开(公告)日：2020-02-04

申请号：US16323750

申请日：2017-07-27

Applicant: AIRBUS DEFENCE AND SPACE SAS

Inventor： Benjamin Gadat ,  Lyonel Barthe ,  Thibault Maisonnat ,  Arnaud Collin

IPC: H04B7/185 ,  H04L27/00 ,  H04L25/02 ,  H04B17/21

Abstract: A method for detecting useful signals in an overall signal. Each useful signal may be affected with a frequency drift. In the detection phase, frequency spectra for detecting the overall signal for multiple detection time windows are calculated and useful signals according to the detection frequency spectra are detected. In the estimation phase, for each useful signal detected: the frequency of the overall signal for multiple frequency drift values is reset. In the estimation phase, for each useful signal detected, a frequency spectrum is calculated for the estimation of the overall signal for each frequency drift value over an estimation time window having the useful signal detected and of a duration higher than the detection time window. In the estimation phase, for each useful signal detected, the frequency drift is estimated affecting the useful signal detected according to the estimation frequency spectra.