Digital sub-band transmission system with transmission of an additional signal

• US 6,691,086 B2
• Filed: 07/19/2001
• Issued: 02/10/2004
• Est. Priority Date: 06/02/1989
• Status: Expired due to Term

• Current Assignee: TDF SAS (Fluor Corporation)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Stoll, Gunther Josef, Lokhoff, Gerardus C. P., Dehery, Yves-Francois
• Primary Examiner(s): MCFADDEN, SUSAN IRIS
• Application Number:
  US09/908,932
• Publication Number:
  US 20010044713A1
• Time in Patent Office: 936 Days
• Field of Search: 704/229, 704/219, 704/220, 704/222, 704/223, 704/230, 375/240.03, 375/240.11, 381/22, 381/23, 370/468
• US Class Current: 704/229
• CPC Class Codes: G10L 19/0204 using subband decomposition
• CPC Class Codes: G11B 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: G11B 2020/10592 specifically adapted for recording or reproducing multichannel signals
• CPC Class Codes: G11B 2020/10601 surround sound signal
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/913 Digital audio tape [DAT] format
• CPC Class Codes: G11B 2220/93 Longitudinal format, wherein tracks are in the direction of the tape, read with a static head, e.g. DCC
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: H04B 1/665 using psychoacoustic properties of the ear, e.g. masking effect
• CPC Class Codes: H04B 1/667 using a division in frequency subbands for TV signals H04N19/63
• CPC Class Codes: H04H 20/88 Stereophonic broadcast systems multiplex system in general H04J
• CPC Class Codes: H04H 40/27 specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95

Abstract

Reproduction accuracy of a digital signal, representing for example stereo audio signals, is improved by transmitting sample data which have been encoded to form transmission signals. The transmission signals are arranged in consecutive frames, each frame including a plurality of information packets, and each information packet including N bits. The number of information packets in a frame is determined by the ratio of the product of the transmission bit-rate and the number of samples represented in the frame, to the product of the number of bits in a packet and the sampling frequency. The transmission signals are recorded in a record carrier, or are transmitted in real time. In a digital stereo audio signal embodiment, the samples may be sub-band encoded or transform encoded. The transmission signal may include an indicator signal indicating a combination of certain samples, or scale factor signals for specific components of the sampled signal.

Claims

1. A digital transmission system having a transmitter and a receiver, for transmitting a wide-band digital audio signal, comprising at least two signal components including a first and a second audio signal component, via a transmission medium, the transmitter comprising:

an encoder having analysis filter means for filtering the signal components to form a number n of sub-signals for each of the at least two signal components;

data reducing means for data reducing the n sub-signals of each of the at least two signal components; and

transmission means for transmitting the data-reduced sub-signals via the transmission medium, and the receiver comprising;

receiving means for receiving the data-reduced sub-signal;

data expansion means for data expanding the received data-reduced sub-signals to form non-data-reduced replicas of the sub-signals; and

a decoder having synthesis filter means for combining sub-signals for each of the at least two signal components to form replicas of the at least first and second signal components, characterized in that the transmitter is further adapted to transmit at least a first auxiliary digital signal component, the transmitter further comprising;

means for generating a composite transmission signal comprising frames, a frame including a first frame portion comprising synchronization information, a second frame portion comprising a block of data of the data reduced sub signals, and a third frame portion located after the second frame portion in said frame, said third frame portion comprising a block of data of the auxiliary digital signal, and the receiver further comprising;

derivation means for deriving said at least one auxiliary digital signal component from third frame portions in frames of the composite transmission signal received.

2. A transmitter for transmitting a wide-band digital audio signal, comprising at least two signal components including a first and a second audio signal component, via a transmission medium, the transmitter comprising:

an encoder having analysis filter means for filtering the signal components to form a number n of sub-signals for each of the at least two signal components;

data reducing means for data reducing the n sub-signals of each of the at least two signal components; and

transmission means for transmitting the data-reduced sub-signals via the transmission medium, characterized in that the transmitter is further adapted to transmit at least a first auxiliary digital signal component, the transmitter further comprising;

means for generating a composite transmission signal comprising frames, a frame including a first frame portion comprising synchronization information, a second frame portion comprising a block of data of the data-reduced sub-signals and a third frame portion located after the second frame portion in said frame, said third frame portion comprising a block of data of the auxiliary digital signal.

3. The transmitter as claimed in claim 2, characterized in that the analysis filter means filters the at least one auxiliary signal component to obtain a number n of sub-signals for each of said at least one auxiliary signal components.

4. The transmitter as claimed in claim 2, characterized in that the data reducing means data reduces the at least one auxiliary digital signal component to form a data-reduced version of the auxiliary digital signal component.

5. The transmitter as claimed in claim 2, characterized in that the analysis filter means filters the at least first and second audio signal components to form a number n of sub-band signals for each of the at least first and second audio signal components, the data reducing means data reduces the n sub-band signals of each of the at least first and second audio signal components, the transmission means transmits the data-reduced sub-band signals via the transmission medium, and the means for generating the composite transmission signal stores a block of data of the data-reduced sub-band signals in the second frame portion.

6. The transmitter as claimed in claim 5, characterized in that the analysis filter means filters the at least one auxiliary signal component to a number n of sub-band signals for each of said at least one auxiliary signal components.

7. The transmitter as claimed in claim 2, characterized in that the transmitter further comprises:

control signal generator means for generating a signal type control signal indicating the type of said at least one auxiliary digital signal component, the transmission means further transmitting said signal type control signal.

8. The transmitter as claimed in claim 2, characterized in that the transmitter further comprises:

control signal generator means for generating a signal presence control signal indicating the presence or absence of said at least one auxiliary digital signal component, the transmission means further transmitting said signal presence control signal.

9. The transmitter as claimed in claim 2, characterized in that the at least one auxiliary digital signal component is a third digital audio signal component.

10. The transmitter as claimed in claim 9, characterized in that the transmitter transmits a first and a second auxiliary digital signal component in the form of a third and a fourth digital audio signal component, respectively, stored in third frame portions of the frames, that the control signal generator means generates a signal type control signal indicating the type of said third and fourth digital audio signal components.

11. The transmitter as claimed in claim 10, characterized in that the first, second, third and fourth digital signal components are the four components of a surround-sound audio signal.

12. The transmitter as claimed in claim 2, characterized in that the data reducing means comprises means for quantizing the respective sub-signals to form quantized sub-signals for each of the at least two audio signal components, in that the second frame portion of a frame comprises allocation information which, for at least a number of sub-signals, indicates the number of bits representing the samples of the quantized sub-signals derived from said sub-signals, and in that the second frame portion comprises the samples of the at least said quantized sub-signals.

13. The transmitter as claimed in claim 12, wherein the sub-signals are in the form of sub-band signals, and the quantization means quantizes the sub-band signals into quantized sub-band signals, characterized in that for at least a number of the sub-band signals, the allocation information in the second frame portion of a frame specifies the number of bits representing the samples of the quantized sub-band signals derived from said sub-band signals, and in that the second frame portion comprises the samples of at least said quantized sub-band signals.

14. The transmitter as claimed in claim 12, characterized in that, in addition, the second frame portion includes information related to scale factors, a scale factor being associated with at least one of the quantized sub-signals contained in the second frame portion, and in that the scale factor information is included in the second frame portion before the quantized sub-band signals.

15. The transmitter as claimed in claim 7, characterized in that the third frame portion of the frames comprises the signal type control signal.

16. The transmitter as claimed in claim 2, characterized in that the third frame portion also includes a scale factor for the at least one auxiliary signal component.

17. The transmitter as claimed in claim 2, characterized in that the third frame portion also includes bit allocation information for the at least one auxiliary signal component.

18. The transmitter as claimed in claim 2, characterized in that the transmitter takes the form of a device for recording the sub-signals and at least the first auxiliary digital signal component in a track on a record carrier.

19. A receiver for receiving a wide-band digital audio signal comprising at least a first and a second audio signal component from a transmission medium, the receiver comprising:

receiving means for receiving a composite transmission signal comprising data-reduced sub signals;

data expansion means for data expanding the received data-reduced sub-signals to form replicas of the sub-signals; and

a decoder having synthesis filter means for combining sub-signals for each of the at least two audio signal components to form a replica of the at least first and second audio signal components, characterized in that the composite transmission signal further includes at least a first auxiliary digital signal component, the composite transmission signal comprising frames, a frame including a first frame portion comprising synchronization information, a second frame portion comprising a block of data of the data reduced sub signals and a third frame portion located after the second frame portion in said frame, said third frame portion comprising a block of data of the auxiliary digital signal, and the receiver further comprising;

derivation means for deriving said at least one auxiliary digital signal component from the third frame portions in the frames of the composite transmission signal received.

20. The receiver as claimed in claim 19, characterized in that the at least one auxiliary digital signal component is in the form of n sub-signals, the synthesis filter means further combining the sub-signals of the at least one auxiliary signal component to form a replica of the at least one auxiliary signal component.

21. The receiver as claimed in claim 19, characterized in that the at least one auxiliary digital signal component received is a data-reduced version of said auxiliary digital signal component, the data expansion means in the receiver further data expanding the received data-reduced version of the auxiliary digital signal component to form said replica of said auxiliary digital signal component.

22. The receiver as claimed in claim 19, characterized in that the receiving means receives sub-band signals for each of the at least two audio signal components, the data expansion means further data expanding the received data-reduced sub-band signals to form said replicas of the sub-band signals, the synthesis filter means further combining the sub-band signals for each of the at least two signal components to form a replica of the at least first and second signal components.

23. The receiver as claimed in claim 19, characterized in that the at least one auxiliary signal component is in the form of a number n of sub-band signals, the synthesis filter means further combining the sub-band signals of the at least one auxiliary signal component to form a replica of the at least one auxiliary signal component.

24. The receiver as claimed in claim 19, characterized in that the composite transmission signal comprises a signal type control signal indicating the type of said at least one auxiliary digital signal component, the receiver further comprising detection means for detecting said signal type control signal, the derivation means deriving, in response to said signal type control signal, said at least one auxiliary digital signal component from the signal received.

25. The receiver as claimed in claim 19, characterized in that the composite transmission signal comprises a signal presence control signal indicating the presence or absence of said at least one auxiliary digital signal component, the receiver further comprising detection means for detecting said signal type control signal, the derivation means deriving, in response to said signal presence control signal, said at least one auxiliary digital signal component from the signal received.

26. The receiver as claimed in claim 24, characterized in that the composite transmission signal comprises a third and a fourth digital audio signal component stored in third frame portions of the frames, the derivation means deriving, in response to said signal type control signal, said third and fourth digital audio signal component from the transmission signal received.

27. The receiver as claimed in claim 19, characterized in that the receiver takes the form of a device for reproducing the sub-signals and at least the first auxiliary digital signal component from a track on a record carrier.

28. A method for transmitting a wide-band digital audio signal comprising at least a first and a second audio signal component via a transmission medium, the method comprising the steps:

filtering the signal components to form a number n of sub-signals for each of the at least first and second signal components;

data reducing the n sub-signals of each of the at least first and second signal components; and

transmitting the data-reduced sub-signals via the transmission medium, characterized in that the method further comprises the steps;

transmitting at least a first auxiliary digital signal component by generating a composite transmission signal comprising frames, a frame including a first frame portion comprising synchronization information, a second frame portion comprising a block of data of the data reduced sub signals and a third frame portion located after the second frame portion in said frame, said third frame portion comprising a block of data of the auxiliary digital signal.

29. A record carrier having a wide-band digital audio signal comprising at least a first and a second audio signal component recorded thereon, the at least first and second audio signal components being filtered into a number n of sub-signals for each of the at least first and second audio signal components and being data reduced to form data-reduced sub-signals, the data-reduced sub-signals being combined together with at least a first auxiliary digital signal into a composite transmission signal, the composite transmission signal comprising frames, a frame including a first frame portion comprising synchronization information, a second frame portion comprising a block of data of the data reduced sub signals, and a third frame portion located after the second frame portion in said frame, said third frame portion comprising a block of data of the auxiliary digital signal.