Abstract: Format converters and methods of performing data format conversion are provided. The format converters may convert compressed data into a different compressed format that is compatible with the Bluetooth transmission standard. The format converter may decompose the compressed data into frequency domain data streams of different frequency sub-bands. The format converter may transform each data stream of frequency domain information from a first encoding scheme to a second encoding scheme, and may then quantize the transformed data steams based on bit allocation information for each sub-band. The format converters may also include a bit allocation component which computes the bit allocation information for each sub-band based on an unfiltered version of the compressed data.

Abstract: The present invention discloses a tagging and identification device and system for tracking and monitoring sea vessels as they enter sea ports, estuaries and/or other channels. The tagging device of the present invention comprises a receiver, for receiving an underwater electromagnetic signal transmitted by an underwater beacon. An acoustic transmitter is provided for transmitting an identification signal to an acoustic receiver deployed nearby. The acoustic identification signal is transmitted after an electromagnetic trigger signal is received from the underwater beacon. The tagging and device may further comprise a memory device which can store data relating to position and time of the see vessel to which it is attached. The tagging and identification device of the present invention is covert, compact and is capable of extended active deployment without replenishment of batteries etc.

Abstract: A speaker device comprises a first speaker (SP1) for reproducing an audio signal and a second speaker (SP2) adapted for reproducing an audio signal and spaced from the first speaker horizontally by a predetermined distance. At least one of the first and second speakers phase has varying means (APF1, APF2, . . . ) for varying the phase of the audio signal by a predetermined quantity of phase according to (i) the frequency of the audio signal and (ii) the predetermined distance.

Abstract: Systems and methods are provided for displaying a short message service (SMS) message on user media equipment, in which the user media equipment includes a set-top box and a display. In some embodiments, the set-top box receives an SMS message, wherein the SMS message includes information identifying a triggering event for displaying the SMS message. The SMS message is stored until the occurrence and detection of the identified triggering event. In response to detecting the occurrence of the identified triggering event, the SMS message is displayed on at least a portion of the display of the user media equipment.

Abstract: A receiving apparatus in a communications system that performs header compression of audio data and has a plurality of operation modes that each have a different frequency of header compression, the receiving apparatus includes: a receiver that receives the audio data, which is transmitted from a transmitting apparatus that performs the header compression; a processor that controls the receiving apparatus in accordance with the process includes: determining a voice-communication state of the received audio data; and changing the operation mode, according to a determination result.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A multi-channel audio decoder provides a reduced complexity processing to reconstruct multi-channel audio from an encoded bitstream in which the multi-channel audio is represented as a coded subset of the channels along with a complex channel correlation matrix parameterization. The decoder translates the complex channel correlation matrix parameterization to a real transform that satisfies the magnitude of the complex channel correlation matrix. The multi-channel audio is derived from the coded subset of channels via channel extension processing using a real value effect signal and real number scaling.

Abstract: In one embodiment, a relationship is determined between radio link protocol (RLP) sequence numbers in received RLP packets and real-time protocol (RTP) sequence numbers in RTP packets decompressed from the received RLP packets. An RTP sequence number associated with a compressed RTP packet is determined based on the determined relationship and at least one of the RLP sequence numbers of the received RLP packet or packets forming the compressed RTP packet. An RTP time stamp may be determined in a similar manner.

Abstract: The present invention provides a communication device and a communication method of an underwater vehicle, which use an electromagnetic field (electromagnetic wave), having a higher propagation speed than that of an acoustic wave, for communication between an underwater vehicle and a mother vessel or the like so as to allow real-time control of the underwater vehicle and the like and further to make the communication little sensitive to noise and the like. The communication device performs wireless communication between an underwater vehicle in water and an object on land or on water, and is configured to compress data to be transmitted and transmit/receive the compressed data by the use of a low-frequency electromagnetic field.

Abstract: An algorithm facilitates optimization functionality for generating optimized response information. In facilitating such optimization, non-essential elements of the response information (i.e., unneeded for system interpretation) are eliminated thereby reducing the size of the response information and generating optimized response information as well as reducing the memory footprint of cache required for storing such optimized response information. Examples of such non-essential elements of response information include, but are not limited to, indention characters, tab characters, blank space characters and the like. Such optimization functionality is tailored to optimizing the size of response information being transmitted from a server. More specifically, it provides for reduction in bandwidth occupied by outgoing response information from a transmitting a server.

Abstract: Systems for an expander circuit are disclosed. An expander circuit comprising a transmit amplifier for amplifying electrical signals received from a microphone. A rectifier circuit is responsive to the electrical signals and generates a D.C. voltage. A dynamic resistor circuit is coupled to the transmit amplifier for regulating the gain of the transmit amplifier. The dynamic resistor circuit includes a bipolar junction transistor for receiving the D.C. voltage. The bipolar junction transistor is operated such that the collector current is zero and the bipolar junction transistor has a variable impedance seen by the transmit amplifier dependent upon the D.C. voltage.

Abstract: A method and apparatus to reduce the overhead of frequently sent signaling messages is provided. Various methods are presented which facilitate conveying information that is unchanged from information in the earlier part of the message, or in a previous signaling message, without sending the previous information in its entirety.

Abstract: In one embodiment, a relationship is determined between radio link protocol (RLP) sequence numbers in received RLP packets and real-time protocol (RTP) sequence numbers of RTP packets represented by the received RLP packets. A RTP sequence number associated with a compressed RTP packet is determined based on the determined relationship and at least one of the RLP sequence numbers of the received RLP packet or packets forming the compressed RTP packet. The compressed RTP packet does not include a RTP sequence number.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A system and method for coding and decoding an information signal sent through a communication system. The system includes: an encoder for encoding the information signal without adding additional information and for sending an encoded information signal; and a soft bit decoder including a-priori information related to the communication system for receiving the encoded information signal and decoding the encoded information signal using the a-priori information.

Abstract: A system and method for relaying signals from a magneto-inductive system, which are normally used to communicate between magneto-inductive units using quasi-static magnetic fields, over a voice-band communication system. The magneto-inductive signals are modulated data signals having a carrier frequency typically between 300 Hz and 3 kHz. The voice-band communication system facilitates long distance communication of voice-band signals. By supplying the signals from one magneto-inductive unit to the voice-band communication system through an analog input port, the signals are transmitted through the voice-band communication system. They are output from the system through an analog audio output port to the other magneto-inductive unit.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: Methods, systems, and computer program products for establishing transcoding free connections between UMA and UMTS call legs are disclosed. According to one method, a media gateway determines whether codec configurations used by UMA and UMTS legs of a call are compatible. In response to determining that the configurations are compatible, media gateway determines whether rate control is necessary to establish a transcoding free connection. In response to determining that rate control is necessary, the media gateway issues rate control requests on the UMA and UMTS legs as appropriate. The media gateway determines whether the rate control requests are successful. In response to determining that the requests are successful, the media gateway establishes a transcoding free connection between the UMA and the UMTS legs of the call.

Abstract: A wireless mobile phone is provided with one or more buttons and complementary logic to facilitate entry of encoded representations of a variable length encoding scheme of alphanumeric data. As a result, a user may use the provided facilities to engage in non-verbal communication for sensitive subject matters in the middle of a call. In one embodiment, the encoded representations are Morse codes. In another embodiment, the encoded representations are custom designed. In one embodiment, the complementary logic further facilitates echoing on a display, alphanumeric data corresponding to any entered encoded representations. Additionally, each of the code entry buttons includes one or more light emitting diodes (LEDs), and the LEDs are lit to visually echo the encoded representations of the variable length encoding scheme of letters, numbers or punctuations entered through a standard input keypad.

Abstract: Disclosed are embodiments of methods and systems for wireless data transmission by magnetic induction. In one embodiment, a network of magnetic induction units is provided. The units may be configured to transmit a data signal by modulation of a time-varying magnetic field. One or more units may also be configured to receive a data signal received from another magnetic induction unit. In one specific implementation, a network of underground magnetic induction units is provided, each having a sensor connected thereto. Each of the units, or a subset of the units, may be configured to transmit its sensed data to an adjacent or nearby unit, which, in turn, may retransmit the original data, along with additional appended data, to another adjacent unit. The network data may thereby be relayed in a multi-hop fashion until it reaches a desired destination.

Abstract: Disclosed is a method for providing heterogeneous services using a PIP function in a terrestrial DMB receiver. The method includes: a first step of receiving a key input for activating the PIP function and displaying a list of services in an available ensemble during use of a desired DMB service; a second step of selecting a desired item in the list of services; a third step of identifying if the desired item selected at the second step is an “exchange” function and identifying if PIP function of the terrestrial DMB receiver is activated when the selected item is the “exchange” function; a fourth step of exchanging a service of a main screen for a service of a PIP screen, when it is identified that the PIP function is activated at the third step; and a fifth step of identifying if the desired item selected at the second step is the “exchange” function and displaying the selected item on the PIP screen when the selected item is not the “exchange” function.

Abstract: A system is presented for utilizing data in a mobile device in real-time and without the need for additional hardware. The system allows real-time processing of highly-compressed data that would otherwise require processing power in excess of that available from the system, or would otherwise not be possible without additional hardware. The system generally includes a processing device that receives the data in a highly compressed format, and includes a preprocessor that pre-processes the data to at least partially decode the data into a second compressed format. The processing device also includes a decompressor that fully decompresses the preprocessed data as needed by the system. The processing device may also include one or more memories for storing the preprocessed data until it is needed by the system.

Abstract: In a method and apparatus for transmission of signals, an input signal is supplied to at least one dynamic compressor and the dynamics of the signal is compressed by the dynamic compressor with a degree of compression. The compressed signal is subsequently adapted, in particular limited, in terms of its frequency bandwidth dependent on the degree of compression, such as directly dependent on the degree of compression or dependent on a reference value directly associated with the degree of compression, such as the input level of the signal before the dynamic compressor.

Abstract: A radio terminal switches between a compressed transmission mode and a normal transmission mode based on the current transmit power level of the radio terminal. The radio terminal periodically compares its current transmit power level to a power threshold. The radio terminal transmits in the compressed transmission mode when the current transmit power level is below the threshold, and transmits in the normal transmission mode when the current transmission power level is greater than the threshold. The radio terminal may also operate in a compressed receiving mode.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: Apparatus, and an associated method, for companding communication data. Companding is provided for a two-way radio communication station operable pursuant to a coded squelch scheme, such as an MURS or FRS radio. A baseband processor invokes compression operations upon originating communication data that is originated at the communication station. And, the processor invokes operation of expansion operations when the communication data comprises terminating data.

Abstract: A method for providing wireless communication between a mobile station and a network station using a context for message compression is provided. Profile-specific information is stored persistently in a profile-specific dictionary. Communication is then provided between the mobile station and the network station using the profile-specific dictionary for message compression.

Abstract: In a case of being judged that a compressed mode is applied in a mobile terminal, if it is judged that reception quality during data communication is favorable, gap intervals are not created by passing through a processing of gap interval creation. Further, if the data communication over the HS-DSCH is performed, the data communication over the HS-DSCH is continued. This prevents degradation of data transmission rate over a channel for high speed data transmission service, in the presence of a mobile terminal in a favorable reception quality area.

Abstract: A method and apparatus to reduce the overhead of frequently sent signaling messages is provided. Various methods are presented which facilitate conveying information that is unchanged from information in the earlier part of the message, or in a previous signaling message, without sending the previous information in its entirety.

Abstract: A pulse train having a specific amplitude is transmitted from a transmitting circuit, and the amplitude at the receiving end is measured by a comparator. A coarse adjustment control unit determines a coarse adjustment value of the pre-emphasis intensity based on the measured amplitude. The pre-emphasis intensity is changed within the course pre-emphasis range, and the maximum receivable time width of a test signal is obtained by a reception judging unit 13 by using a fine adjustment stage.

Abstract: To provide “transparent” broadcast services for a multi-mode wireless device capable of communicating with multiple wireless communication networks, a composite set of pertinent parameters for broadcast messages used by the multiple networks is defined. The parameters of the broadcast message for each network are mapped to corresponding parameters in the composite set. The composite set of parameters is used for processing and displaying broadcast messages received from the multiple networks. A broadcast message for each network (e.g., a CBS message in GSM or a broadcast SMS message in CDMA) is received and processed in accordance with the parameters of the message and filtering configurations applicable for the network. The parameters of the broadcast message are mapped to corresponding parameters in the composite set. The broadcast message is further processed and displayed based on the parameters in the composite set.

Abstract: A method and system for providing header compression guidance to mobile devices initiating certain applications and/or protocols. A selective header compression (SHC) utility utilizes a session initiation protocol (SIP) message to provide robust header compression (ROHC) guidance to a mobile device initiating a call involving selected (SIP related) applications, protocols and/or service options. In addition, ROHC guidance allows the mobile device to appropriately select the source and/or destination port (depending on packet origination) for data flows requiring ROHC. ROHC guidance may recommend that the mobile device request ROHC for VoIP flows, but not for video flows. Furthermore, the guidance may specify the range of real-time protocol (RTP) ports at which ROHC is applied. For example, within a specified range of RTP ports, ROHC may be applied to data transmissions via even port numbers but prevented for real-time transport control protocol (RTCP) flows via odd port numbers.

Abstract: The invention provides a method of processing messages. The method includes the step of obtaining a subscriber message, from a subscriber communication device over a telecommunications network, the subscriber message representing a voice message from a subscriber. The subscriber message is stored in computer memory and then presented in an audio form to a human operator. A data file is composed which is derived from the subscriber message and the data file transmitted to a subscriber computing device and/or the subscriber communication device. The invention provides a related system for processing messages.

Abstract: A cryptographic system, method, and device for implementing cryptographic functions designed to protect data is provided. The method includes (a) providing an algorithm processing unit, (b) executing a cryptographic algorithm at the algorithm processing unit using a first cryptographic datum and input data to form output data, (c) determining if a context switch command is received from a controller, (d) receiving a second cryptographic datum from a memory if the context switch command is received, (e) replacing the second cryptographic datum with the first cryptographic datum if the context switch command is received, and (f) repeating (b)-(e). The controller switches the processing state of the algorithm processing unit from one channel to another channel without leaking data between channels through execution of the operations each time a channel switch is selected. As a result, a single algorithm processing unit used with a controller can provide multiple independent levels of security.

Abstract: Disclosed is an apparatus and method for transmitting/receiving a control message in a wireless communication system that is designed to reduce overhead associated with transmission/reception of the control message. To this end, a transmission apparatus generates a control message, generates a compressed control message by compressing the generated control message, based on a control message that has been lastly received by a reception apparatus from among previously transmitted control messages, selects one of the generated control message and the generated compressed control message according to whether or not the control message lastly received by the reception apparatus exists, and transmits the selected one of the generated control message and the generated compressed control message to the reception apparatus. Therefore, it is possible to reduce resources used for control message transmission, and thus increase the use efficiency of the resources.

Abstract: Compander architecture and method for ensuring that the components of an output signal are synchronized includes calculating a gain calculation for an input signal, detecting a predetermined condition such as a zero crossing or absence of a zero crossing within a specified period, and ensuring that the result of the gain calculation is providing to the system synchronously with the input signal. The input signal may be divided into one or more signals for processing, and the gain calculation may include one or more power estimations and one or more gain cells associated with the multiple signals, and may further include variable attack and release.

Abstract: A processor within a wireless terminal performs data compression, decompression and error correction according to a data compression protocol such as the V.42bis data compression protocol used within GSM wireless networks. This processor includes an interface that receives incoming information or data to be compressed or decompressed according to the data compression protocol. A processing module within the processor is operably coupled to the interface to receive and process the incoming information. Instructions executed within the processing module will divide the processing responsibilities between the processing module and a data compression/decompression accelerator operably coupled to the processing module. Compute intensive operations may be offloaded from the processing module onto the data compression/decompression accelerator to improve overall system efficiency.

Abstract: A base station monitors the uplink load and sends control signals to one or more mobile terminals to selectively enable and disable compressed mode operation. The base station can divide the mobile terminals into groups and can assign different compressed mode patterns to different groups of mobile terminals so that the transmissions from mobile terminals in different groups while in compressed mode are not synchronized. If load imbalances occur, the network can reassign mobile terminals from one group to another.

Abstract: A header compression in a broadband wireless communication system is provided. A transmitter includes a compressor for compressing a header of a packet; a processor for appending a compression channel IDentifier (ID) to the packet; and a controller for identifying a Service Flow (SF) corresponding to the compression channel ID and processing the packet according to the SF. Accordingly, by using the ID of the compression channel in the header compression, the SF can be identified even in the header compression.

Abstract: A robust header compression scheme (“ROHC”) compresses IP security (“IPSec”) protected IP packets. More specifically, ROHC is applied to portions of an IP packet header prior to IPSec encryption. ROHC may then optionally be applied again to the unencrypted portions of the IP packet.

Abstract: The present invention relates to a method for transmitting signals in a wireless communication system, in which signals are transmitted from a first communication device to a second communication device, said signals being transmitted in consecutive frames, each frame having a preamble section comprising preamble information, at least one of said first and said second communication devices having a narrow beam antenna which is adapted to be steered to different positions, each of said different positions corresponding to one of a number of different transmission paths from said first to said second communication device, comprising the steps of transmitting and receiving a first preamble section comprising preamble information enabling the estimation of a channel quality of a current transmission path, while said narrow beam antenna is in a current position corresponding to said current transmission path, steering said narrow beam antenna from said current position to a different position corresponding to a ca

Abstract: A signal transmission arrangement includes a signal transmitter and a signal receiver wirelessly communicating with the signal transmitter. The signal transmitter includes a hybrid signal device to hybridize the audio signal with the control signal to form a consolidating signal, a frequency modulator to high-frequency modulate the consolidating signal, wherein the consolidating signal is amplified and sent to the signal receiver in a wireless manner. The signal receiver includes a frequency demodulator to demodulate the consolidating signal and a signal dissociating unit to dissociate the consolidating signal to restore the audio signal and the control signal. Therefore, the signal transmission arrangement provides a low-bit rate coding transmission in control signals, in lieu of the high-bit rate coding transmission which requires the expensive high performance integrated circuit, so as to ensure the quality of the audio signal while being cost effective.

Abstract: The present invention provides a novel system, method and apparatus of delivering interactive voice response services in a more efficient manner over a network. The system provides for the placement of a subscriber station local 28 to the subscriber and a gateway protocol converter at the base station 40. The gateway protocol converter converts bandwidth-intensive audio messages into compact data messages, which upon transmission to the subscriber station 28 are converted back into audio messages. By using data messages instead of audio messages over the network, bandwidth is saved on the network for other traffic. Another embodiment of the invention provides a method for transmitting subscriber responses utilizing the system.

Abstract: A current mirror with selectable filter poles provides a selected low pass filtering function to a DC bias signal generated by the current mirror. Coupled between a first MOSFET and second MOSFET of the current mirror, a low pass filter with selectable filter poles comprises a plurality of resistor-configured MOSFETs coupled to at least one capacitor-configured MOSFET to provide one of a fast settle time and improved filtering for the current mirror in one embodiment of the invention. A first resistor-configured MOSFETs, biased by logic and bias circuitry, provides a low frequency filter pole that provides an improved filtering for the current mirror. A second resistor-configured MOSFET provides a high frequency filter pole that provides a fast charge time to meet a settle time requirement.

Abstract: A packed based data transmission scheme is proposed which comprises a method of transmitting data in a packet based communication network system through a tunnel between a receiving node (40; 210) and a sending node (10;110) communicating with each other via a communication network, said method comprising the steps of: generating (S10) an original packet to be sent to said receiving node, said original packet comprising a first header as an inner header indicating and a payload, generating (S20) a tunneled packet by encapsulating said original packet with a second header as an outer header, said outer header indicating an intermediate network station for the transmission of said tunneled packet, processing (S30) said tunneled packet for the transmission by compressing said inner header and by compressing said outer header and by generating a compressed packet.

Abstract: A method of operating a mobile telephone that is taken up in a data transmission network, which method involves at least one encoding and decoding algorithm for converting analog speech data into digital data and vice versa; according to this method at least one further encoding and decoding algorithm is transmitted to the mobile telephone via a data transmission link that is established between the mobile telephone and the network, which algorithm is received by the mobile telephone and stored in a non-volatile memory so as to be used for data conversion after the implementation.

Abstract: The device (10) for digital demodulation comprises a polyphase filter (14) comprising a set of N distinct elementary digital filters and means (16) of selection, for each block of an elementary digital filter (Hi). It comprises a decimating stage (18) for selecting samples in each block on completion of the digital filtering and means (20) for determining samples to be selected comprising means (28) for computing an error signal for each filtered block and means (31) for evaluating the error signal suitable for determining the samples to be selected in the relevant block. That the means (16) of selection of an elementary digital filter (Hi) comprise means (28) for calculating an error signal. The means (28) for calculating an error signal are common to the means (16) of selection of the elementary digital filter (Hi) to be implemented and to the means (20) for determining samples to be selected. Application to a mobile telephone or base station.

Abstract: Described is a transmission system (10) comprising a transmitter (12) for transmitting a narrowband audio signal to a receiver (14) via a transmission channel (16). The receiver (14) comprises a frequency domain bandwidth extender (18) for extending a bandwidth of the received narrowband audio signal by complementing the received narrowband audio signal with a highband extension thereof. The bandwidth extender (18) comprises an amplitude extender (24) for extending the bandwidth of an amplitude spectrum of the received narrowband audio signal by mapping narrowband amplitudes onto highband amplitudes. The bandwidth extender (18) further comprises a phase extender (26) for extending the bandwidth of a phase spectrum of the received narrowband signal and a combiner (28) for combining the extended amplitude spectrum and the extended phase spectrum into a bandwidth extended audio signal.

Abstract: The device (10) for digital demodulation comprises a polyphase filter (14) comprising a set of N distinct elementary digital filters (Hi) and means (16) of selection, for each block of an elementary digital filter (Hi). These latter comprise means (28) for computing an error signal, means (30) for comparing performance indicators for the digital filters arising from the error signals and means (30) for determining the elementary digital filter (Hi) to be implemented in respect of the following block as a function of the result of the comparison. The digital filters (Hi) are ordered. They are chosen according to the order of the filters, as a function of the result of the comparison performed on the performance indicators for the elementary digital filters (Hi) implemented in respect of at least one previous block. Application to a mobile telephone or base station.