Radio broadcasting system and method providing continuity of service
AssigneeThales
InventorPierre-André Laurent
Life of this patent
Estimating the term…
Abstract
A system and method to provide continuity of service in a radio broadcasting system, wherein the radio broadcasting system includes at least one modem using the COFDM technique, and transmits N time-frequency cells modulated independently of one another. A number N1 of cells conveying digital audio signal S1 and a number N2 of cells conveying analog audio signal S2 are transmitted to a receiver. When the receiver cannot decode the signal in the N1 cells, the receiver replaces the digitized audio signal S1 with the analog signal S2.
Claims11
A method to provide continuity of service in a radio broadcasting system, wherein the radio broadcast system includes at least one modem using a COFDM technique, and said radio broadcasting system is configured to transmit N time frequency cells modulated independently of one another, the method comprising:
- at transmission,
- sending a number N1 of cells conveying signals for transmission of a digitized audio signal S1, and
- sending a number N2 of cells conveying signals for transmission of an analog signal S2;
- at reception,
- differentiating, in a received signal Sr, between at least the digitized audio signal S1 and the analog signal S2;
- replacing the digitized audio signal S1 by the analog signal S2 conveyed by the cells N2 when the signals of the N1 cells cannot be decoded,
- wherein a proportion of cells N1 for a passband of about 10 kHz ranges from 50% to 80% of a quantity N of available cells.
A method to provide continuity of service in a radio broadcasting system, wherein the radio broadcast system includes at least one modem using a COFDM technique, and said radio broadcasting system is configured to transmit N time frequency cells modulated independently of one another, the method comprising:
- at transmission,
- sending a number N1 of cells conveying signals for transmission of a digitized audio signal S1, and
- sending a number N2 of cells conveying signals for transmission of an analog signal S2;
- at reception,
- replacing the digitized audio signal S1 by the analog signal S2 conveyed by the cells N2, when the signals of the N1 cells cannot be decoded, wherein
- at transmission, one or more preprocessing steps are performed, including introducing a delay for the analog signal S2.
A radio broadcasting system including at least one modem using a COFDM technique, said modem being represented in a time frequency space by several elementary cells comprising N available cells, wherein the system comprises:
- a transmitter, wherein said transmitter includes,
- a device configured to distribute signals for transmission of a digitized audio signal S1 in a number N1 of cells and signals for the transmission of analog audio signals S2 in a number N2 of cells;
- and
- a device configured to obtain a compression of a dynamic range of the analog audio signal S2,
- a receiver, wherein said receiver includes,
- a device configured to differentiate, in a received signal Sr, between at least the digitized audio signal S1 and the analog audio signal S2,
- a device configured to determine if the digitized audio signal S1 is in decodable form, and
- a device configured to replace the digitized audio signal S1, which is not in decodable form, with the analog audio signal S2.
A radio broadcasting system comprising including at least one modem using a COFDM technique, said modem being represented in a time frequency space by several elementary cells comprising N available cells, at least one transmitter and at least one receiver, wherein the system comprises at least one of the following elements:
- a transmitter, wherein said transmitter includes,
- a device configured to distribute signals for transmission of a digitized audio signal S1 in a number N1 of cells and signals for the transmission of analog audio signals S2 in a number N2 of cells and
- a device configured to introduce a delay into the analog audio signal S2, said transmitter further includes at least one of,
- a lowpass filter at the receiver configured to filter the analog audio signal S2,
- a system configured to sample the analog audio signal S2, and
- a device configured to obtain a compression of a dynamic range of the analog audio signal S2;
- a receiver, wherein said receiver includes,
- a device configured to differentiate, in a received signal Sr, between at least the digitized audio signal S1 and the analog audio signal S2,
- a device configured to determine that the digitized audio signal S1 is in decodable form, and
- a device configured to replace the digitized audio signal S1, which is not in decodable form, with the analog audio signal S2.
A radio broadcasting system comprising including at least one modem using a COFDM technique, said modem being represented in a time frequency space by several elementary cells comprising N available cells, at least one transmitter and at least one receiver, wherein the system comprises at least one of the following elements:
- a transmitter, wherein said transmitter includes,
- a device configured to distribute signals for transmission of a digitized audio signal S1 in a number N1 of cells and signals for the transmission of analog audio signals S2 in a number N2 of cells;
- a receiver, wherein said receiver includes,
- a device configured to differentiate, in a received signal Sr, between at least the digitized audio signal S1 and the analog audio signal S2,
- a device configured to perform a windowing on the received signal Sr on a portion of the received signal that is supposed to be stable,
- a device configured to determine if the digitized audio signal S1 is in decodable form,
- a device configured to replace the digitized audio signal S1, which is not in decodable form, with the analog audio signal S2, and
- a device configured to perform processing operations on the analog audio signal S2, wherein said processing operations include at least rejecting background noise.
Dependencies are inferred from the claim text.