Abstract: A method and system for providing window shaping for multiline transmission in a communications system are described. A last portion of a prefix symbol is extracted. A prefix with a prefix window is shaped to create a shaped prefix. A DMT symbol is shaped with a DMT window to create a shaped DMT symbol. The shaped DMT symbol is combined with the shaped prefix.

Abstract: The punctured pilot channel comprises information symbols of uncertain sign punctured into a sequence of pilot channel symbols of predetermined sign. The apparatus includes an information sign demodulation circuit for determining the sign of the information symbols in response to the pilot channel symbols. A continuous pilot generator generates a non-punctured pilot channel of predetermined sign from the information symbols and the pilot channel symbols. In a first embodiment, the information sign demodulator further comprises a dot product circuit for calculating a dot product of the pilot channel symbols and the punctured information symbols, and a threshold comparator for comparing the dot product to a predetermined threshold.

Abstract: An intermediate station transmits a supervisory signal sent form a given controlled device to a controlled device associate with the given device as a control signal. An intermediate-station input unit extracts a supervisory signal, which is a current signal superimposed on a signal transmitted through a data signal line, in every clock cycle. An intermediate-station output unit obtains the supervisory signal in every clock cycle, and outputs a control signal, which is a pulse-width-modulated voltage signal, onto the data signal line in the same clock cycle in which the supervisory signal has been extracted.

Abstract: A receiver contains a demodulator system that can deliver a stream of digital data comprising at least a first and a second audio program. If a user selects the first audio program, the receiver applies a first bit rate decompression to generate a stream of decompressed digital data. If the user selects the second audio program, the receiver applies a second bit rate decompression to generate a different stream of decompressed digital data. A digital to analog converter can be used to generate the corresponding analog signals.

Abstract: A transmission parameter recognition apparatus and the method thereof are disclosed. The transmission parameter recognition apparatus includes a correlation function processing module, a correlation symbol summing module and an energy interval detection module. The correlation function processing module computes a correction between two adjoining symbols in a sample sequence to generate a correlation function sequence. The correlation symbol summing module accumulates M symbols in the correlation function sequence to generate an energy interval. Since the distribution of the energy interval is related to the guard interval type, therefore, the energy interval detection module detects the distribution of the energy interval to generate a piece of guard interval information.

Abstract: A wavelet domain watermark encoder and decoder embed and detect auxiliary signals in a media signal, such as a still image, video or audio signal. A watermark orientation signal is embedded in a wavelet decomposed signal to facilitate detection of the watermark in a geometrically distorted version of the embedded signal. In some configurations, the watermark signal forms a pattern in a transform domain used to perform synchronization of the watermark. The pattern has attributes used to determine orientation of the watermark in a geometrically distorted version of the media signal. The attributes carry two or more auxiliary message symbols in the watermark, and the attributes both carry the two or more auxiliary message symbols and form the pattern used to perform synchronization of the watermark.

Abstract: A mobile station, and corresponding system and method, the mobile station including an IQ multiplexer configured to IQ multiplex transmission data for a data channel and control data for a control channel, and to generate a complex signal; and a transmitter configured to modulate the complex signal generated by the IQ multiplexer, and to transmit the modulated complex signal. When control data for a control channel are added, the IQ multiplexer is configured to assign the control data to be added to the Q axis when a set number for the data channel is an odd number, and to the I axis when an even number.

Abstract: A system for transmitting and receiving control data in a TDM communications network includes a single master TDM multiplexor and one or more slave TDM muliplexors. The master station stimulates the one or more slave stations, and only one station can transmit control data at any given time. Both slave and master TDM multiplexors include (i) a receiver component for extracting control data from the TDM signal and passing this control data to a control processor; (ii) a transmitter component for inserting control data from a control processor into the TDM signal; and (iii) a bridging component for passing control data along to the next TDM multiplexor without the need for control processor intervention. The system allows a single node in the network to communicate with and control all the nodes in the network. The system can control other TDM sub-networks using secondary communication links.

Abstract: When a scrambler (54) performs IQ multiplexing of output signals from a spreader 52 and a distributor 53 in order to generate a complex signal (I signal and Q signal), amplitude coefficients ?cc(I) and ?cc(Q) are determined in accordance with signal powers on I axis and Q axis.

Abstract: A multiplex superposed communication device receives a data packet from a Local Area Network (LAN), analyzes the data packet, and extracts transmission destination information. A setting table includes a setting of a relation between the transmission destination information and multiplex signal channels. A signal channel to be used for relaying a communication signal is determined in accordance with the setting table. The communication signal is superposed on a power line and transmitted using the determined signal channel. When relaying data packets addressed to the same transmission destination, the same signal channel is used. Accordingly, each signal channel is reserved for each registered transmission destination.

Abstract: A method transmitting a message over at least one of a plurality of radio frequency (RF) channels of an RF communications network is provided. The method comprises the steps of detecting a presence of jamming pulses in the at least one of the plurality of RF channels. The characteristics of the jamming pulses in the at least one of the plurality of RF channels is determined wherein the determined characteristics define at least interstices between the jamming pulses. The message is transmitted over the at least one of the plurality of RF channels wherein the message is transmitted within the interstices of the jamming pulse determined from the step of determining characteristics of the jamming pulses.

Abstract: A wireless telemetry system includes many radio transmitters using frequency-hopping carriers for intermittently transmitting very short messages indicative of status of stimuli associated with the transmitters. The transmitters can transmit independently of any receiver for receiving from the transmitters and independently of each other. Transmission frequency and time between transmissions are varied according to time-frequency patterns that can be different for each transmitter. Urgent messages, such as alarms, are transmitted at transmission opportunities at intervals smaller than routine transmissions. The transmission opportunities are also according to a time-frequency pattern. Power-up transmissions carry information about future transmission opportunities and/or routine transmissions. Power-up transmissions can also carry information about time-frequency pattern for controlling routine transmissions and/or transmission opportunities.

Abstract: A mobile station, and corresponding system and method, the mobile station including an IQ multiplexer configured to IQ multiplex transmission data for a data channel and a control data for control channel, and to generate a complex signal; and a transmitter configured to modulate the complex signal generated by the IQ multiplexer, and to transmit the modulated complex signal. When control data for a channel are added, the IQ multiplexer is further configured to assign the control data to be added to the I axis or the Q axis according to whether a set number for the data channel is an odd number or an even number.

Abstract: A mobile station, and corresponding system and method, the mobile station including an IQ multiplexer configured to IQ multiplex transmission data for data channels, control data for a control channel, and control data for an exclusive control channel for high speed downlink packet data, and to generate a complex signal; and a transmitter configured to modulate and transmit the complex signal generated by the IQ multiplexer. The IQ multiplexer assigns the transmission data for the data channel to the I axis and the Q axis, alternately, and assigns control data to the Q axis. When control data for high speed downlink packet data are added, the IQ multiplexer assigns the control data for high speed downlink packet data to the Q axis when a set number for the data channel is an odd number and to the I axis when the set number is an even number.

Abstract: A digital data system comprises a plurality of links for passing messages between nodes, which may be end points such as memory or processing units, or intermediate or branch points such as routers or other devices in the system. A link level flow control is implemented by control symbols passed between adjacent nodes on a link to efficiently regulate message burden on the link. The control symbols may be embedded within in a message packet to quickly effect control on a link—such as reducing data flow, requesting retransmission of corrupted data, or other intervention—without disruption of the ongoing packet reception. A control symbol may be recognized within the packet by a flag bit, a marker such as a transition in a signal, or a combination of characteristics. The control symbol may be a short word, having a control action identifier code at defined bit positions to indicate the desired link-level control function.

Abstract: An optical multiplex communication system includes a multiplexer and a demultiplexer. In the multiplexer, one of two modulated optical pulse train signals is attenuated by an optical attenuator so that amplitudes of the two signals differ from each other. Then, the two signals are time-division multiplexed to produce a multiplexed optical pulse train signal. In the demultiplexer, a VD detector indirectly derives the amplitude of the extracted optical pulse train signal and outputs it to a comparator. A VR detector derives the mean amplitude of the multiplexed optical pulse train signal and outputs it to the comparator. Based on the inputted amplitudes, the comparator identifies the extracted optical pulse train signal. A controller and a mixer control the signal extraction timing such that the extracted optical pulse train signal as identified by the comparator agrees with selection designated by an externally inputted select signal.

Abstract: In an array-antenna base-station apparatus 100, a relay-station apparatus 110 and a control-station apparatus 120 are connected with optical cables 140, 150, and, moreover, calibration of the whole apparatus 100 is performed to improve the performances of the above whole apparatus 100.

Abstract: A radio transmission system including many radio transmitters using frequency hopping carriers to intermittently transmit very short messages indicative of status of stimuli associated with the transmitters. The transmitters transmit transmissions independently of a receiver receiving the transmissions and independent of each other. In operation, radio transmitters transmit messages at varying frequencies at time intervals that can be varied as well. The frequency and time intervals are varied according to patterns that can be determined individually for each transmitter. A receiver holds data indicative of the future transmission frequency and time for each transmitter and updates the data based on the time and the content of the received messages. In addition, a simple method is provided to generate a very large number of orthogonal frequency-time hopping sequences that are individual for each transmitter and based on the transmitter ID.

Abstract: A method of superimposing additional information on a video signal, transmitting it, and detecting the additional information from the transmitted video signal. The additional information is synchronized with a sync signal in the video signal, and generated in N (N?1) unit intervals of one field of the video signal. Some predetermined unit intervals of the additional information generated in N (N?1) unit intervals of one field of the video signal, are phase-inverted. The additional information is identified by detecting the information in unit intervals based on the sync signal in the video signal, and detecting that information in some predetermined unit intervals is inverted. The additional information is identified by detecting the information in unit intervals, and integrating the detection results with the information in inverted predetermined unit intervals inverted.

Abstract: A method increases the wireless information carrying capability of a single bit-limited message by providing a plurality of different training sequences TS, such as a conventional 41 bit TS and two new 41-bit TSs, each with low cross-correlation and high auto-correlation. One of the TSs is selected, appended to an 11-bit Packet Channel Request message, and transmitted. The message with TS is detected and the message is interpreted in light of the TS. In EGPRS, selection of TS1 indicates one of a one-phase access request (OPAR), a short access request (SAR), or a two-phase access request (TPAR) with 8-PSK modulation capability on the uplink. Selection of TS2 indicates one of OPAR, SAR, or TPAR with GMSK modulation capability only on the uplink. Selection of TS_GSM indicates one of GPRS, OPAR, SAR or TPAR, or one of a page response, cell update, mobility management procedure, or a single block without a TBF establishment message.

Abstract: A system and method for implementing a control channel in a packet switched communications network. In a computer network, such as a local area network (LAN) it is known to utilize the Ethernet for distributing communications between stations. The Ethernet employs a standard frame format that includes header frames and, in particular a preamble frame which may be used to provide synchronization information between switching devices or nodes. The preamble frame is not required in a Gigabit Ethernet implementation and the present invention employs a portion of the preamble frame to implement a control channel between switching devices.

Abstract: Physical layer structures and related access schemes for unsynchronized communication networks are provided. Access channel information, preferably including a common synchronization code associated with all transceiver stations in a communication network and a cell-specific synchronization code uniquely associated with one of the transceiver stations, is modulated onto at least one set of time-continuous signal components of a communication signal. In order to access the communication network, communication terminals search for the access channel information in one or more sets of time-continuous signal components and synchronization parameters are then determined based on a location of the access channel information in the sets of time-continuous signal components. Some embodiments of the invention provide for joint frame synchronization and coarse timing synchronization.

Abstract: An asynchronous transfer mode (ATM) switch includes a switch memory having a plurality of discrete queues. A queue is dedicated to a connection in which a traffic stream is transmitted in cells and an inverse multiplex ATM (IMA) format. A switch controller is operable to receive a plurality of cells, to identify cells for the connection, to queue cells for the connection in the queue based on order information received with the cells, to reconstitute from the queue the traffic stream, and to switch the traffic stream and the ATM cells.

Abstract: An apparatus comprising a parallel arrangement of circuits is described. Each circuit has a data net input. Each circuit has an indication signal net input configured to transport an indication signal having shapes and/or temporal locations different than a data signal on the data net input.

Abstract: To reduce power consumption of a first line driver/receiver (LD1) adapted to communicate with a second line driver/receiver (LD2) via a transmission line (1) in a multitone communication system, wherein, during a training sequence, the second line driver is adapted to transmit a known multitone signal pattern to the first line receiver, a signal processor (DSP1) connected to the first line driver/receiver (LD1) is adapted to measure the signal-to-noise ratio of the received signal pattern and, in response hereto, determine an appropriate bit rate to be used, to decrease the quiescent current of the first line driver in steps, to detect a decrease of the measured signal-to-noise ratio, and to set the quiescent current of the first line driver to the value it had before the decrease of the signal-to-noise ratio was detected.

Abstract: Clock information related to a reference clock is distributed from a master network node to a slave network node in an asynchronous packet-based network by embedding the clock information into an additional bit stream and multiplexing the additional bit stream with a primary data stream using an out-of-band channel. Multiplexing the additional bit stream with the primary bit stream using an out-of-band channel may involve selecting yB codes of an xB/yB encoded bit stream to represent bits of the additional bit stream or to balance the running disparity of the xB/yB encoded bit stream. The clock information that is embedded into the additional bit stream is used to generate a clock that is synchronized with a reference clock. In an embodiment, the clock information represents the time difference between a transmitted frame of the additional bit stream and a next edge of the reference clock.

Abstract: A control device for driving a self-starting motor for an engine is provided with a control means 4. If a starting switch 7 is switched ON when a start enabling signal of a start limiting means 5 and a non-start signal of a start detecting means 6 are in an output condition, the control means 4 puts a starting relay 3 which supplies a starting motor 1 with electricity in the ON-state for a predetermined time, only when the start enabling signal and the non-start signal are in the output condition.

Abstract: Interleaving methods and apparatus are disclosed for an in-band on-channel digital audio broadcasting system. The guard periods that separate any two adjacent symbols in a conventional OFDM system can provide a mechanism for OFDM frame synchronization. The guard period of successive OFDM frames is utilized to establish one or more unique positive or negative patterns and thereby provide a mechanism for interleaver synchronization. By proper positioning of the guard period patterns, one or more particular portions of each interleaver block are identified, such as the beginning and midpoint of each interleaver block. The present invention identifies the beginning of each interleaver block, for example, by positioning the fourth negative cyclic prefix with OFDM frame zero (0). The present invention can optionally identify the midpoint of each interleaver block, for example, by positioning the fourth negative cyclic prefix with OFDM frame 206.

Abstract: A mobile station transmits a pilot signal, a common channel signal and a traffic channel signal for a reverse link. The mobile station normally transmits the common channel signal and the pilot signal at a predetermined transmission power, and transmits the pilot signal at a transmission power higher than the predetermined transmission power over a predetermined duration. The pilot signal transmitted over the predetermined duration is spread with a first spreading code over the duration where the pilot signal is transmitted at the predetermined transmission power, and is spread with a second spreading code over the duration where the pilot signal is transmitted at the transmission power higher than the predetermined transmission power.

Abstract: A method, apparatus, and article of manufacture used to encode/decode a low activity communication signal—such as a Baudot tone—for transmission over a telecommunications system. The telecommunications system may include any number of wireless links. Once the system is noticed that a low activity signal needs to be transmitted, each vocoder used in the system to encode/decode the signal performs a unique encoding/decoding process. In one embodiment, frames containing errors adversely affecting a signal are delivered to the vocoder and the “soft bits” contained therein are used to determine the original signal transmitted. In another embodiment, encoding of the signal may include encoding the signal using redundancy with the encoded signal being spread across multiple vocoder frames.

Abstract: In an arrangement for securing an ADSL connection to an ADSL transceiver connected together with a telephone to a common telephone line; there are devices for setting a first number and a second, lower number, respectively, of bits to be allocated to the ADSL connection. Moreover, there are devices for detecting whether or not a ringing signal is present on the line and whether the telephone is in the off-hook or the on-hook condition. The first number of bits is allocated when neither the ringing signal nor the off-hook condition is detected, and the second, lower number of bits is allocated when the ringing signal and/or the off-hook condition is detected.

Abstract: A transmission system using nQAM. A control channel is superimposed on a nQAM data channel. It is desirable to separate control channel data from user data without using a higher level protocol layer. In multi-carrier systems with variable bit-loading it is particularly desirable that the control channel data be separable from user data when the value of n. that is the bit-loading, or constellation identifier are unknown. Binary data is transmitted using nQAM modulation. The binary data includes both user data and control data. This means that a control channel is superimposed on a user data channel within the same nQAM constellation. Separation of the control data is facilitated by arranging control data points to have either a unique phase or unique amplitude values. These unique values are not employed for user data points.

Abstract: A digital signal encoding, editing and transmitting method enabling seamless coupling of plural video bitstreams without causing disruption of a decoder buffer. In coupling a second bitstream from an encoding unit 20 to the trailing end of a first bitstream from an encoding unit 10, an encoding unit 12 imposes limitations in encoding for securing a data buffer volume required for startup of the second bitstream in the vicinity of the trailing end of the first bitstream responsive to the control signal from a terminal 14, while an encoding unit 22 imposes limitations in encoding for securing a data buffer volume required for startup of the second bitstream in the vicinity of the leading end of the second bitstream responsive to the control signal from a terminal 24.

Abstract: A system for seamlessly splicing two encoded video streams. In one implementation of the system, one or more coding parameters are extracted from the first and/or second encoded streams and one or more parameters of the first and/or second encoded streams are changed in accordance with the extracted parameter(s) in order to effectuate seamless splicing. In another implementation, the coding parameters applied to the first encoded stream are referenced when encoding the second stream such that the resulting second encoded stream can be seamlessly spliced with the first encoded stream.

Abstract: A new additional information generating section generates new additional information FS1 based upon information from an additional information reading section. The spectrum of the new additional information FS1 is spread by an SS additional information generating section and supplied to a signal superimposing section as SS additional information SF1. The signal superimposing section generates a digital video signal S2 by superimposing the SS additional information SF1 on a digital video signal S1. A writing section records the digital video signal S2 on which the SS additional information SF1 is superimposed on a recording medium. Hereby, adding additional information to an information signal without deteriorating the quality of the read information signal so that the falsification and deletion are disabled, detecting the additional information added to the information signal if necessary and utilizing it are enabled.

Abstract: The present invention relates to a method of inserting sync patterns of different lengths in modulated data, and a recording medium having sync patterns produced by said method. The sector sync and the frame sync pattern to be inserted in modulated data in accordance with the present invention must satisfy the given (d, k) constraints, have distinctive 0's run the modulated channel data can not have, and be as short as it can. In addition, the frame sync pattern is shorter than the sector sync pattern because the frame sync pattern is more frequently inserted than the sector one. Owing to the present sync patterns, the storage capacity reduction of a recording medium due to necessary insertion of sync patterns can be minimized under a given modulation condition.

Abstract: A method and apparatus is presented for burying a hidden data stream into a combined network data stream. In the preferred embodiment, the network data stream is an MPEG-2 type video data stream, and the hidden data stream is embedded so that it is neither readily detectable nor easily removable from the network data stream. A home gateway having a wireless transceiver communicates with appliances in the home via this network data stream. The hidden data stream can be embedded with a main data stream either by the content provider or by the gateway in the home. At the appliance, the hidden stream can be removed and is presented to or used by the user in a way appropriate for the appliance. Instructions as to how the hidden stream is to be presented on the appliance can be embedded into the hidden stream itself. The hidden data stream can be further used to control access to and control the content of the rest of the network data stream.

Abstract: The invention relates to a method of switching from a first to a second video sequence, in which it is provided, in order to avoid the creation of special access points such as splicing points defined in MPEG standard, to insert at the switching point, between the two sequences, an additional sequence of k pictures. These pictures, said minimal in that sense that they are coded with a reduced number of bits, may be for instance uniform colour pictures or the repetition of a single previous I or P picture.

Abstract: A new additional information generating section generates new additional information FS1 based upon information from an additional information reading section. The spectrum of the new additional information FS1 is spread by an SS additional information generating section and supplied to a signal superimposing section as SS additional information SF1. The signal superimposing section generates a digital video signal S2 by superimposing the SS additional information SF1 on a digital video signal S1. A writing section records the digital video signal S2 on which the SS additional information SF1 is superimposed on a recording medium. Hereby, adding additional information to an information signal without deteriorating the quality of the read information signal so that the falsification and deletion are disabled, detecting the additional information added to the information signal if necessary and utilizing it are enabled.

Abstract: In order to increase accuracy of DC-offset compensation within radio receivers and to ensure that such compensation does not erode the dynamics of the decoders located within the receivers, the present invention separately performs mean value estimation and channel estimation. Additionally, a bias DC offset value caused by the use of a training sequence to perform mean value estimation can be corrected for in the channel estimator and equalizer.

Abstract: A method for combining signals being conveyed across a digital interface is disclosed. In one embodiment, a subharmonic of a frequency is superimposed on asynchronous data. The subharmonic can be used to carry a frequency reference across the digital interface. In another embodiment, a time stamp algorithm is used to carry a time reference from a master circuit to a slave circuit across a digital interface. The transmission delay between the master circuit and slave circuit is measured. The master circuit transmits time correction messages to the slave circuit, based on the time the correction message is transmitted plus the transmission delay. In another embodiment, a reset signal is carried across a digital interface by discontinuing the transfer of a frequency reference for a predetermined time. A lowpass filter can be used at the receiving side of the interface to recognize the absence of the frequency reference and initiate a reset procedure at that side.

Abstract: The invention relates to a TDMA method, transmitter and receiver, wherein a training sequence is modulated and superposed on a data signal to thereby generate a TDMA burst. Thereby, the training sequence can be made longer and is always available during data reception, such that longer channel impulse responses can be measured. In the transmitter, the training sequence is separately modulated in a modulating means (3) before being superposed on the data signal. The receiver comprises an extracting means (11) for extracting the superposed training sequence and a cancelling means (9) for cancelling the training sequence from the data signal to be detected.

Abstract: A method of superimposing additional information on a video signal, transmitting it, and detecting the additional information from the transmitted video signal. The additional information is synchronized with a sync signal in the video signal, and generated in N (N≧1) unit intervals of one field of the video signal. Some predetermined unit intervals of the additional information generated in N (N≧1) unit intervals of one field of the video signal, are phase-inverted. The additional information is identified by detecting the information in unit intervals based on the sync signal in the video signal, and detecting that information in some predetermined unit intervals is inverted. The additional information is identified by detecting the information in unit intervals, and integrating the detection results with the information in inverted predetermined unit intervals inverted.

Abstract: The punctured pilot channel comprises information symbols of uncertain sign punctured into a sequence of pilot channel symbols of predetermined sign. The apparatus includes an information sign demodulation circuit for determining the sign of the information symbols in response to the pilot channel symbols. A continuous pilot generator generates a non-punctured pilot channel of predetermined sign from the information symbols and the pilot channel symbols. In a first embodiment, the information sign demodulator further comprises a dot product circuit for calculating a dot product of the pilot channel symbols and the punctured information symbols, and a threshold comparator for comparing the dot product to a predetermined threshold.

Abstract: A transmission system for transmitting a data signal with an analog passband signal through a analog transmission line. The data signal is transformed to a signal representing a descrete data signal point in a vector signal space. The analog passband signal is transformed to a base band signal, and the base band signal is superimposed on the signal representing a descrete data signal point. A signal representing the superimposed data signal point is modulated and transmitted through the analog transmission line. In a receiver, the data signal point is decided from the signal representing the superimposed data signal point, and the superimposed bass band signal is extracted by subtracting the decided result from the signal representing the superimposed data signal point. The base band signal is transformed to the analog passband signal. A portion of information carried by the analog passband signal may be converted to a digital signal, and the digital signal is multiplexed with the data signal.

Abstract: A method of superimposing additional information on a video signal, transmitting it, and detecting the additional information from the transmitted video signal. The additional information is synchronized with a sync signal in the video signal, and generated in N(N≧1) unit intervals of one field of the video signal. Some predetermined unit intervals of the additional information generated in N(N≧1) unit intervals of one field of the video signal, are phase-inverted. The additional information is identified by detecting the information in unit intervals based on the sync signal in the video signal, and detecting that information in some predetermined unit intervals is inverted. The additional information is identified by detecting the information in unit intervals, and integrating the detection results with the information in inverted predetermined unit intervals inverted.

Abstract: In transmitting communication signals to a receiver via a transmission channel, the transmitter generates a composite signal including information from which the receiver can determine a channel evaluation signal and other control information. The composite signal is transmitted over the transmission channel. This results in improved channel capacity, reduced power transmission requirements, and reduced interference in the transmission channel.

Abstract: A masked signal transceiver of the present invention comprises a transmitter for transmitting a combined signal of a primary communications signal and an attenuated secondary communications signal occupying substantially the same frequency band concurrently. A receiver receives the combined signal and demodulates the primary communications signal to extract the primary communications signal information. An adaptive locally optimum processor separates the secondary communications signal from the combined signal. The secondary communications signal is then demodulated to extract the secondary communications signal information.

Abstract: A billing system for use in a chargeable program broadcasting is capable of reliably billing a subscriber for program reception while preventing unauthorized reception thereof. A receiving terminal includes a primary terminal 100 and a secondary terminal 150. The primary terminal 100 receives a compressed video signal and confirms by an error checker 113 thereof whether there is a transmission error and bills, by a billing device 114 thereof, the receiving subscriber on the basis of an error information and a program information, etc., separated from the video signal by a separation circuit 112. The compressed video data is time-axis multiplexed with a terminal identifying code and a key signal and transmitted to the secondary terminal 150. In the secondary terminal 150, a bill for the subscriber is confirmed by the terminal identifying code and the compressed data is decoded by a decoder circuit 166 thereof.

Abstract: The present invention is embodied in a method an apparatus for reducing the number of leased E1 lines needed to backhaul communication traffic in a satellite communication situation. The present invention receives and decompressed a satellite signal. A copy of the compressed signal is then encoded into the least significant bits (LSBs) of the decompressed signal. The decompressed signal having the embedded information may be routed to an international PSTN network over leased communications lines. However, the compressed information is extracted from the decompressed signal and sent across the E1 lines, thereby conserving communication bandwidth and reducing the number of leased lines required. After passing through the E1 lines the information is decompressed and connected to the international PSTN network. Alternatively, the decompressed signal having the embedded information may be distributed to local PSTN networks, which interpret decompressed signals.