摘要:
Methods and arrangements for processing a signal using a digital processor having a given word length. The signal is pre-processed using a pre-processor which reduces the word length and performs an operation which is invariant with respect to a process being performed by the digital signal processor. This means that if the pre-processor operated with infinite accuracy, it would have no effect on the subsequent process. If such a pre-processor operates with infinite accuracy, it will reduce the guantization noise. In the digital signal processor, the pre-processed signal may be transformed into frequency coefficients which are normalized directly thereafter.
摘要:
The invention relates to a method of storing data on a rewritable data storage medium, to a corresponding storage medium, to a corresponding recording apparatus and to a corresponding playback apparatus. Copy-protective measures require that on rewritable storage media some data must be stored which shall not be modifiable or erasable by consumer end products. A practical problem is the storage of large quantities of such data in a fixed data area. Typically the capacity is limited to a few bits. Meanwhile the amount of copy protection data that needs to be stored may well exceed the storage capacity available in the read-only fixed data area. The invention therefore proposes to write the copy protection data as system data in the recordable data area (4), e.g. as part of the formatting of the medium (1). A cryptographic summary is computed and also stored in the recordable data area (32) or in the fixed data area (2) such that a cryptographic relationship between the fixed data area (2) and the system data area (3) is provided. A playback or replay apparatus will only accept a storage medium with a valid combination of copy protection data and fixed data.
摘要:
The invention relates to a method of storing data on a rewritable data storage medium, to a corresponding storage medium, to a corresponding recording apparatus and to a corresponding playback apparatus. Copy-protective measures require that on rewritable storage media some data must be stored which shall not be modifiable or erasable by consumer end products. A practical problem is the storage of large quantities of such data in a fixed data area. Typically the capacity is limited to a few bits. Meanwhile the amount of copy protection data that needs to be stored may well exceed the storage capacity available in the read-only fixed data area. The invention therefore proposes to write the copy protection data as system data in the recordable data area (4), e.g. as part of the formatting of the medium (1). A cryptographic summary is computed and also stored in the recordable data area (32) or in the fixed data area (2) such that a cryptographic relationship between the fixed data area (2) and the system data area (3) is provided. A playback or replay apparatus will only accept a storage medium with a valid combination of copy protection data and fixed data.
摘要:
Described is a transmission system for transmitting a multicarrier signal from a transmitter (10) to a receiver (20). The multicarrier signal comprises a plurality of subcarriers. The receiver (20) comprises a channel estimator (28) for estimating amplitudes of the subcarriers and for estimating time derivatives of the amplitudes. The receiver (20) further comprises an equalizer (24) for canceling intercarrier interference included in the received multicarrier signal in dependence on the estimated amplitudes and derivatives (29). The channel estimator (28) and/or the equalizer (24) are arranged for exploiting an amplitude correlation between the derivitives of different subcarriers. By making use of this correlation the complexity of the receiver (20) can be substantially reduced.
摘要:
A method and arrangement for detecting a watermark in a suspect signal, in which the watermark is embedded by adding a watermark pattern w to a signal p with a given embedding strength s (“additive embedding”: q=p+sw), includes correlating (2,3) it with the suspect signal. Recently, “multiplicative embedding” has been proposed (q=p(1+sw)). In this case, multiplicatively embedded watermarks are detected by raising (1) the signal to a power &bgr; prior to correlating it with the watermark. The power &bgr; may be fixed (e.g., &bgr;=2) or derived from a statistical analysis (5) of the signal.
摘要:
In an apparatus and a method for reproducing user data stored in encrypted form on a recording medium, in order to provide a higher level of protection against hacking of user data and, in particular, of decryption keys, which are used for encrypting said user data and which are also stored on the recording medium, an integrated unit calculates a decryption key using key data read from the recording medium, decrypts the user data read from said recording medium using the calculated decryption key, andre-encrypts the decrypted data using a re-encryption key. The re-encrypted data and the re-encryption key are then transmitted to an application unit for decrypting the re-encrypted data using the re-encryption key and for reproducing the decrypted data.
摘要:
Coded light has been proposed to enable advanced control of light sources and transmit information using light sources. It is based on invisibly embedding of data and identifiers in their light output. Methods, devices and systems configured to efficient assignment of addresses in a coded lighting system, still allowing for unique identification, are proposed. More specifically, the assignment of addresses occurs in two phases, where in the initial phase wide area unique addresses are used, while in the second phase only local area unique addresses are used. Also, methods, devices and systems configured to efficiently distribute a set of addresses over a set of light sources in this second phase, to maximize the performance of the illumination contribution estimation, and positioning, are disclosed.
摘要:
The invention relates to a method of outsourcing intermediate results of an internal data processing to an external memory, to a corresponding device for processing data having an interface for outsourcing intermediate results, to a disk drive having a corresponding device for processing data, and a cellular phone having a device for processing data. This method can be applied when confidential data is processed but intermediate results thereof need to be stored externally to the processing. First intermediate result data units (I1) are combined with first verification data units (V1) in order to provide a data signal (S1), which is encrypted (E1) and stored in an external memory (5). When the intermediate result data units (I1) stored in the external memory (5) are needed during a subsequent internal data processing a data signal (E2) is read from the external memory (5). After the decryption of the read data signal second verification data units (V2) and second intermediate result data units (I2) are obtained. Said second read verification data units (V2) are verified with said first verification data units (V1) in order to detect any manipulation of the intermediate result data during the time that they were stored in the external memory (5).
摘要:
Coded light has been proposed to enable advanced control of light sources and transmit information using light sources. It is based on invisibly embedding of data and identifiers in their light output. Methods, devices and systems configured to efficient assignment of addresses in a coded lighting system, still allowing for unique identification, are proposed. More specifically, the assignment of addresses occurs in two phases, where in the initial phase wide area unique addresses are used, while in the second phase only local area unique addresses are used. Also, methods, devices and systems configured to efficiently distribute a set of addresses over a set of light sources in this second phase, to maximize the performance of the illumination contribution estimation, and positioning, are disclosed.
摘要:
Proposed is an illumination system (100) comprising a plurality of light sources (10) provided with encoders (20) arranged to enable light emitted from the light sources to comprise light source identification codes. In order to enable light effect commissioning, i.e. correlating the light sources (10) with their illumination footprints (11), the system further comprises a camera (40) arranged to register images of illumination spots (11), and a signal processor (111) arranged to derive the light source identification codes from registered images. Arranging the encoders (20) to modulate the light emitted at a frequency above a predefined high level to comprise fast codes (12) and at a frequency below a predefined low level to comprise slow codes (13), beneficially allows for the use of simple low cost camera systems.