Abstract: A circuit arrangement for phase modulation in an input circuit of a backscattering transponder includes a varactor and at least one capacitor connected in series between two antenna terminals, and at least two voltage sources selectively connected through at least two switches to at least one terminal of the varactor. A control unit selectively opens and closes the switches in response to the data to be phase-modulated onto the backscattered signal. By selectively connecting the different voltage values of the respective voltage sources to the varactor terminal(s) through the switches, the capacitance of the varactor and correspondingly the input impedance of the input circuit are thereby varied, so as to provide respective different phase positions of the phase modulation.

Abstract: A portable medication compliance device (10) having a body (12) and compartments (22) formed in the body. A microprocessor (120) is disposed in the body (12) and is coupled to each of the compartments (22). The microprocessor (120) is programmable to determine relative time intervals for dispensing medication from each of the compartments, to notify the user when a dose of medication is to be taken from each of the compartments, and to record the opening of each of the compartments in a memory. Programming buttons (24) are positioned proximate the body and are coupled to the microprocessor (120). The programming buttons (24) enable a user to program the microprocessor. The device may also be programmed via a remote computer through communication means (47A). A display means (16) such as a Liquid Crystal Display (LCD) is positioned on the body and is coupled to the microprocessor (120).

Abstract: A non-invasive powerline communications system includes: means for generating communication signals at a first location for transmission on a powerline; means for reactively coupling the communication signals to the powerline; and means for receiving said communication signals at a second location.

Abstract: The present invention refers to a method for defining useable frequency bands for a powerline communication (PLC) system (101) using power supply lines of a power supply network (104a) for interconnecting a number of PLC nodes (302, 306) such that electromagnetic emissions generated by PLC signals (s(t)) transmitted via said power supply lines do not interfere with broadcast RF signals radiated in the same frequency bands. Before starting own communication activities, PLC nodes (302, 306) participating in a PLC session scan (S1a) the entire frequency range designated for powerline communication to detect (S1b) frequency bands which are occupied by broadcast services. During powerline communication the occurrence of broadcast signals is regularly checked (S2) by screening (S2a) the entire frequency range designated for powerline communication and detecting (S2b) relevant broadcast bands that should be omitted during powerline communication to avoid interference noise (n(t)).

Abstract: A system and method for alerting responsible personnel to perform a post-trip inspection check for passengers remaining on a bus at the end of a trip by issuing audible and/or visual alerts when the bus is parked and the motor shut off at the end of the trip. The ignition switch (47) must be placed in ACCESSORY position and a park brake applied for the system to be rendered capable of being disarmed by operation of a disarming device (45S) at the rear of the bus. Operation of the disarming device is indicated by a correct sequence of operating conditions of the device, namely first non-actuated, then actuated, and then non-actuated. The system includes a SNOOZE state that allows the ignition switch to be temporarily turned off during a trip and the alert to be stopped by pressing a snooze switch.

Abstract: A vision-based object detection decision-making system (10) for a vehicle (12) includes multiple vision sensing systems (14) that have vision receivers (20) and that generate an object detection signal. A controller (16) includes a plurality of sensing system aid modules (18) that correspond to each of the vision sensing systems (14). The controller (16) operates the sensing system aid modules (18) in response to a vehicle parameter and generates a safety system signal in response to the object detection signal. The sensing system aid modules (18) have associated operating modes and operate the vision sensing systems (14) in the operating modes in response to the vehicle parameter.

Abstract: A crash notification system (12) for an automotive vehicle (10) is used to communicate with a communication network (22) and ultimately to a response center (24). The system (12) within vehicle (10) includes an occupant sensor (30) that generates an occupant sensor status signal. A crash sensor (34) a vehicle identification number memory (48), or a vertical acceleration sensor (46) may also be used to provide information to the controller (14). The controller (14) generates a communication signal that corresponds to the occupant sensor status signal and the other information so that appropriate emergency personnel may be deployed.

Abstract: In a method for controlling a safety system in a vehicle, wherein an output signal of at least one impact sensor is subjected to frequency analysis in an evaluation unit which is integrated into an electronic control unit, the frequency analysis is performed in at least one predetermined frequency range, the spectrum of the output signal is compared with references patterns, the dependence of the spectrum on the present speed of the vehicle and/or the present outside temperature of the vehicle is taken into account, and a triggering signal is generated from the control unit to trigger planned protective measures if a person to be protected is detected with at least a predetermined probability.

Abstract: A pneumatic tire mountable of the rim of a vehicle wheel has a toroidal structure including a pair of beads for receipt on the rim of a vehicle wheel such that the pneumatic tire is secured to the vehicle wheel for rotation therewith. The pneumatic tire also includes a tread band surface at the radially outermost location of the toroidal structure for contacting a surface along which the tire rolls. A plurality of sensor elements are disposed in the tire for sensing at least one operational parameter of the tire, with at least some of the sensor elements being in sensing arrangement with the tread band surface and the sensor elements being operable to permit reading of data concerning any tire operational parameter which is sensed by the sensor elements.

Abstract: An integrated LED warning and vehicle lamp according to aspects of the present invention has a base configured to directly replace an existing vehicle lamp by reception into the lamp's reflector shell. The integrated warning and vehicle lamp includes a first radial array of LEDs dedicated to producing the vehicle warning and/or illumination formerly produced by the vehicle lamp and a second radial array of LEDs dedicated to producing an emergency warning light signal. The second radial array may be electrically connected to an axial LED. The LEDs are supported by a lamp support at a location near the focus of the reflector shell. An interface electrical circuit modifies the electrical energy formerly fed to the vehicle lamp to a form appropriate for the LEDs in the first array. A warning signal electrical circuit energizes the second array of LEDs to produce the emergency warning light signal.

Abstract: A warning beacon includes a transparent housing, having a triangular shape suggestive of a warning sign, the housing having a front face, a back face, and side edges. A mounting plate is disposed within the housing between the front and back faces, and a plurality of LEDs are supported by the mounting plate, and oriented to provide light in at least a forward direction through the front face.

Abstract: A system and method for providing security utilizing stigmergic behavior. A plurality of sensors is adapted to communicate with one another. Each sensor may be elevated from a stable state corresponding with a secure environment into an elevated state corresponding with a first detection event. Each sensor after detecting a first detection event communicates with another sensor in order to elevate the other sensor into the elevated state. An alarm signal is generated in response to one or more second detection events subsequently occurring within the security system.

Abstract: An invention that automatically reports and collects security surveillance problems, device diagnostics and device state information from cameras and security detection equipment. Devices may be attached to a network or attached through a device controller on a network but are not limited to that topology. Each detected occurrence is recorded for analysis and reporting to network administration centers. The device or the controller may also keep track of trend information and report that over time. The administration center produces warning alerts and notifications. These alerts and notifications may not be related to a single problem or intrusion but may be based on trend, predictive or diagnostic information using predictive algorithms. Special charts, graphs, histogram and other reports are produced by the system to aid in proactive diagnosis, problem prediction and behavior patterns.

Abstract: A method of testing the interconnect between remotely distributed hazardous condition detectors is provided. The method utilizes the detector's self-test button to initiate a detector self-test. Once the self-test is complete, the detector's alarm is silenced and an interconnect test signal is sent to the interconnected remote hazardous condition detectors. The transmission of this signal continues so long as the test button remains depressed. The remote detectors, on receipt of this signal, sound their alarm. The user, with the local detector's alarm now silenced, is better able to hear the remotely interconnected detector's alarm.

Abstract: A packet intrusion detection rule simplification apparatus and method and an intrusion detection apparatus and method are provided. Test conditions of at least one intrusion detection rules are rearranged based on test items, and the same test conditions for the same test items are grouped. Group rules having a connection structure of the test conditions are generated so that the test items and orders of the intrusion detection rules are satisfied. A common rule consisting of test conditions existing at the test start positions in the connection structure of the group rules is generated. Next, packet intrusion detection is performed by using the common rule, and the packet intrusion detection is performed by using the group rules. According, it is possible to reduce a load involved in the intrusion detection process by using the grouped and simplified intrusion detection rules.

Abstract: An emergency alarm system is disclosed as including a base unit 9, adapted to be installed in an architectural structure at an area attracting public attention, which incorporates a temperature sensor 29, a gas sensor 31, a sound sensor 33 and a vibration sensor 35 and includes a transmitter 39, a receiver 41, a sound generator 37 and a display board 27; a mobile handset 23, carried by a person for self-defense, which incorporates a temperature sensor 51 and a gas sensor 53 and includes a transmitter 59, a receiver 61, a sound generator 55 and a light source 57; and infrared ray sensors 13, installed in respective rooms in the architectural structure, which incorporates a temperature sensor 69 and a gas sensor 71 and includes a transmitter 73; wherein when one of the sensors of the base unit 9, the mobile handset 23 and the infrared ray sensors 13 detects an abnormal signal under an emergency condition, the base unit 9, the mobile handset 23 and the infrared ray sensors 13 mutually communicate with each other

Abstract: A security system for monitoring a premises. Alarm information, including a near real-time feed of video and/or audio data, is collected at the premises and retrieved by a remotely located monitoring computer workstation over a data network. If desired, a remotely located emergency response computer workstation coupled to the data network may be authorized, by the monitoring computer workstation, to retrieve the collected alarm information over the data network. The emergency response computer workstation may also be granted control of the alarm information collecting devices located at the monitored premises.

Abstract: An emergency interrupt system, for supplying emergency information to a person while using an electronic device, and monitoring the electronic device with a monitor device. The emergency interrupt system is connected between the electronic device and monitor device, and obtains an audible visual signal from the electronic device. The emergency interrupt system receives an emergency radio signal, decodes audio and visual emergency information therefrom, and composites said information with the audible visual signal. The user then monitors the composited information with the monitor device.

Abstract: A multipurpose sensing system of detecting, qualifying and quantifying a potential threat to national security comprises a multipurpose sensing module associated with each cargo carrying container. The system tracks the instantaneous location of each cargo carrying container with the multipurpose sensing module on board each cargo carrying container sampling the contents thereof for the presence of material selected from the group comprising nuclear, biological and chemical grade weapons material.

Abstract: An electronic security system that would alert a homeowner that someone is attempting to gain access to their home. The system includes a transmitter positionable within a dead bolt housing within a doorjamb of an existing door assembly. The transmitter is engaged when a dead bolt is positioned within the dead bolt housing in a locked orientation. The transmitter emits a signal once the dead bolt is removed from the dead bolt housing. A receiver is in communication with the transmitter. The receiver has an internal alarm enunciator. The receiver receives the signal from the transmitter thereby activating the internal alarm enunciator upon removal of the dead bolt from within the dead bolt housing.

Abstract: A medication tracking and/or medical assistance device and method comprises an RFID tag coder for reading from and/or writing to an RFID tag. A processor and a memory process information read from an RFID tag to provide a message based thereon by a visual and/or an audible message.

Abstract: A radio frequency indentification (RFID) label includes an integrated circuit and an antenna. The label may also include two flexible films directly sealed to each other. The label may be affixed to an article and used in conjunction with an interrogation system to track the article.

Abstract: An electronic diagnostic device for testing electronic monitoring tags for devices such as replaceable modules for a printing apparatus includes a tag reader with a reader wireless communication element. The tag reader is adapted to read tag diagnostic information from an electronic monitoring tag. The electronic diagnostic device further includes a data processor in communication with the tag reader. The data processor is adapted to determine from the tag diagnostic data whether the electronic monitoring tag is operating within predetermined parameters, to identify one of a predetermined set of error categories if the electronic monitoring tag is operating outside the predetermined parameters, and to generate error category information. The electronic diagnostic device further includes a results communication element adapted to communicate the error category information generated by the data processor. The diagnostic device may also communicate correction information to the electronic monitoring tag.

Abstract: An RFID device, such as an RFID tag or label, includes a combined reactive coupler electrically coupling a transponder chip to an antenna. The combined reactive coupler includes a magnetic coupler and a capacitive coupler. The magnetic coupler and the reactive coupler may have respective coupling elements on both the interposer and on an antenna substrate.

Abstract: An asset tracking system is provided, having particular usefulness in connection with the marking and tracking of sealing gaskets of the type used in water and sewage systems and in fluid conveyance systems generally. Interrogation of RFID tags located on the sealing gaskets insures that the gaskets are properly tracked, identified and sorted.

Abstract: When an information providing server 20 according to the present invention acquires attribute information items of RFID tags 51 to 59 detected in a shopping cart and in the vicinity thereof, it transmits these attribute information items to a rule server 30. When the received attribute information items satisfy a predetermined combination, the rule server 30 returns presentation information corresponding to the combination to the information providing server 20. When the information providing server 20 receives this presentation information, it sends the presentation information to a mail address of mobile equipment 70 acquired from the attribute information items. This permits the user to readily figure out a dish that can be made from cooking ingredients put in the cart.

Abstract: An RFID tag inspection system inspects the properties of tag antennas, and further, determines the communication performance of RFID tags, based on how much their resonant frequencies are shifted from a target value. The RFID tag inspection system includes: a reader/writer including a coiled reader/writer antenna, for transmitting/receiving data to or from the RFID tag at the resonant frequency through the reader/writer antenna; an RFID tag set portion on which the RFID tag is set in such a way that the tag antenna is located within a coverage area of the reader/writer antenna; and a magnetic field sensing coil including at least one open terminal, the magnetic field sensing coil being placed corresponding to the tag antenna.

Abstract: A web of radio frequency identification (RFID) devices includes a conductive layer atop an insulating layer, the conductive layer having one or more apertures therein. Alternatively, the web may not include an insulating layer. RFID chips or straps are electrically coupled to portions of the conductive layer on either side of an aperture, for use as antennas when the RFID devices are separated from one another, as by cutting. The apertures may be formed by creasing portions of the web, and removing parts of the creased portion. There may be one or more apertures in a longitudinal or transverse direction of the web. The antenna shapes of various of the RFID devices may be tessellated, nesting within one another or having the same boundary, thereby improving efficiency by using substantially all of the conductive material. The RFID devices may be tested and/or programmed while remaining in the web format.

Abstract: Sensing devices 1a, 1b, . . . , 1n for sensing a person 2 moving close to a plurality of previously selected locations and receivers 4a, 4b, . . . , 4n for receiving identification data transmitted from an identification tag 3 co-operate to acquire behavior data indicative of the movement pattern of a person 2, and a processing device 6 compares the behavior data to reference data relating to an authorized person previously identified by the identification data, in order to determine whether or not the result of the comparison indicates the existence of a difference. Then, when the processing device determines that the result of the comparison does not indicate the existence of a difference, it does not transmit the image data acquired via cameras 5a, 5b, . . . , 5n disposed in predetermined locations to a delivery system 8.

Abstract: Among plural liquid leakage sensors placed at the lower most portion of a system such as a floor surface, a leaked liquid storing portion, etc., an error-activated location of the sensor can be easily identified uniquely when the sensor is detecting any abnormality. In a liquid leakage detecting system including at least one liquid leakage sensor having at least one detecting portion contactable with a leaking liquid through an air layer or a liquid permeable layer, a warning device including a sound producing is placed within a specified spatial distance from each installation position of the liquid leakage sensor, wherein after detecting any abnormal conditions of the liquid leakage sensor, a warning signal is issued at least in an audio frequency based on the warning device in order to discriminate the error-activated leakage sensor from other non-activated leakage sensors placed outside of the specified spatial distance and uniquely identify the installation position of the activated leakage sensor.

Abstract: Due to the presence of various environmental condition detectors in the home and businesses such as smoke detectors, carbon monoxide detectors, natural gas detectors, etc., each having individual but similar sounding alarm patterns, it can be difficult for occupants of such dwellings to immediately determine the specific type of environmental condition that exists during an alarm condition. The present invention comprises an environmental condition detector using both tonal pattern alarms and pre-recorded voice messages to indicate information about the environmental condition being sensed. Single-station battery-powered and 120VAC detectors are described as are multiple-station interconnected 120 VAC powered detectors. The pre-recorded voice messages describe the type of environmental condition detected or the location of the environmental condition detector sensing the condition, or both, in addition to the tonal pattern alarm. Provisions are made for multi-lingual pre-recorded voice messages.

Abstract: A protection device for a communication circuit that includes a sensor monitoring a protection device parameter and an indication module coupled to the sensor. The indication module generates an indication output as a function of the protection device parameter indicating a protection device event. The indication module receives power from an indication power source separate from the telecommunication signal. Also a method for protecting a telecommunication signal with a protection device including sensing a protection device parameter indicating a protection device event. The method also includes powering an indication module from an indication power source that is separate from the telecommunication signal. The method further includes generating an indication output from the indication module as a function of the protection device parameter indicating the protection device event.

Abstract: The invention relates to a voltage regulator for physically remote loads (2) with an adjustable power supply (9) for the load (2), with a measurement device (11, 12) assigned to the load (2) for creating a digital measurement signal, which is transmitted over a digital data channel (13) arranged between a data source (15) and a data sink (17) to a setting device (18 to 20) for the power supply (9).

Abstract: A method, system and computer program product for adaptively tracking the position of an entry portal, such as an automatic garage door. In accordance with the present invention a transmitter assembly senses and transmits the sensed position of the door position in a periodic manner at a predetermined transmit interval. A receiver assembly including a receiver module receives the transmitted door position signals and synchronizes the activation of the receiver module with the transmit interval such that the receiver receives the door position signals transmitted at the predetermined transmit interval. A receiver output indicator is then updated in accordance with the entry portal position determined by the received door position signal.

Abstract: A handle on doors, hoods, or the like especially for vehicles, with a stationary handle part, which can be mounted in a recess in the outer skin of the door, with a gripping element, which acts as a movable handle part and is supported on the stationary handle part, with an electrode of an electrical field-generating capacitor, located in the area of the stationary handle part, and with an electronic circuit for generating and monitoring this electrical field. The electronic circuit responds to the approach of a human hand to the gripping element and, if the response is positive, initiates defined functions in the motor vehicle. The electrode of the capacitor is integrated into a supplemental housing, and the supplemental housing is selectively locatable on the surface of the stationary handle part by the connector.

Abstract: A method and apparatus for maintaining an ideal frequency ratio between numerically-controlled frequency sources provides a mechanism for maintaining coherence between multiple synchronization references where a known ideal rational relationship between the sources is known. Multiple numerically controlled oscillators (NCOs) generate the multiple synchronization references, which may be clock signals or numeric phase representations and the outputs of the NCOs are compared with a ratiometric frequency comparator that determines whether there is an error in the ratio between the NCO outputs. The frequency of one of the NCOs is then adjusted with a frequency correction factor provided by the ratiometric frequency comparator. The NCO inputs can represent ratios of the synchronization reference frequencies to a fixed reference clock and the NCOs clocked by the fixed reference clock.

Abstract: A master entity is capable of broadcasting commands to slaves which move to another state when they satisfy a primitive condition specified in the command. By moving slaves among three sets, a desired subset of slaves can be isolated in one of the sets. This desired subset of slaves ten can be moved to one of the states that is unaffected by commands that cause the selection of other desirable subsets of slaves. In the incorporated U.S. Pat. Nos. 5,550,547 and 5,673,037, certain subgroups of radio frequency tags are selected for querying, communicating, and/or identifying by commands from a base station.

Abstract: The present invention provides a remote control system capable of controlling a number of devices on a network by one remote controller. A remote controller (10) requires a controlled device (20) defined as an object to be controlled to send display information. Thus, the display information stored in a ROM (21) of the controlled device (20) in advance is read and transmitted to the remote controller (10). The display information is described in a language such as HTLM, JAVA or the like. A browser on the remote controller (10) side displays a screen indicative of functions corresponding to a plurality of function keys (11) on a liquid crystal display (12). Thus, the function is selected based on the screen displayed on the liquid crystal display (12), and the function key (11) corresponding to the function is depressed, thereby making it possible to control the controlled device (20).

Abstract: Apparatus for conducting geophysical surveys comprising a multiplicity of intelligent electrodes provided on a multi-conductor cable, for receiving a command signal in response to which predetermined electrodes are connected to selected conductors in the cable. Each intelligent electrode is identical in all respects, including its programming, resulting in simplified construction of the cable and easy replacement of the intelligent electrodes. Instead of assigning a unique address code to each switch in a series of take-outs on a multi-conductor cable, each electronic switch is programmed with the same address code. That is, each switch is programmed to be activated when it receives a code command that, for example, is prefaced with a particular address, e.g. the number 1. The second part of the code (y) instructs the switch as to which conductor in the multi-conductor cable is to be connected to the local electrode at the location of the switch.

Abstract: The invention includes a wireless communication circuit and a method of communicating with wireless signals that feature a tank circuit having an inductor connected in parallel with a capacitor circuit. The capacitor circuit includes a pair of capacitors coupled in series. Each of the capacitors is connected in common to ground and has a capacitive value associated. A feedback network is connected to selectively bias the tank circuit to produce a signal having an amplitude. The amplitude of the signal is a function of a ratio of the capacitive values associated with the capacitor circuit. The frequency of the signal is defined by the inductor and the capacitor circuit. The tank circuit is multifunctional in that it may be biased to function as a transmitter and a receiver.

Abstract: A revenue meter includes electronics for measuring the delivery of electrical energy from an energy supplier to a consumer through an electric circuit, a display and a cover. The electronics includes at least transducers, an analog to digital converter and logic. A meter cover encloses the revenue meter. Communications of data to and from the revenue meter may be done via a fiber optic communications link.

Abstract: A host vehicle system includes a lane change system providing an indication to the host vehicle a target vehicle entering a destination lane. The system includes arrays of magneto-resistive sensors on both sides of the vehicle receiving proximity information as a function of magnetic field variations, a vehicle bus receiving various vehicle control signals, a smart algorithm controller analyzing bus signals and sensor signals, and various vehicle collision systems such as passive restraints, optical light guides, and audible warnings operating in response to a threat from a target vehicle.

Abstract: A system, method and display for monitoring the performance of an aircraft during the take-off maneuver that includes the steps of monitoring the progress of the take-off maneuver by acquiring data representative of the aircraft's motion at a plurality of points during the maneuver, generating a function that best fits the acquired data, and using the generated function to predict future progress of the maneuver.

Abstract: A system for monitoring an aircraft receives navigation signals and deriving a position vector therefrom and also asserts an alert signal in the event that the altitude of the aircraft above ground level is less than a predetermined value. The system samples the position vector at a selected sample rate and outputs a succession of samples of the position vector, the sample rate depending on whether the alert signal has been asserted. Data packets that contain respective samples of the position vector are transmitted to a ground-based receiving station. The ground-based receiving station may calculate secondary data.

Abstract: This invention describes a method for a touch actuation in an electronic device using a general purpose input board. The input board comprises of a grating of conductors running in one direction (y-lines). Between these conductors there are contacts connected to a grating running in the perpendicular direction a layer below (x-lines). The grating layers are separated by an insulating layer. The input board can be manufactured using a wide variety of technologies, e.g., printable resistive, conductive and insulating materials. Various known methods can be used to read the position of any conductive actuator touching the input board. The input board can be used as a configurable UI board under a keymat. The input devices on the keymat can be a key, a joystick, a touchpad top membrane, etc. and their configurations and positions can be freely varied on switchcovers. In addition, the actuators can be made force-sensitive by detecting a contact surface area.

Abstract: A key switch 102 formed by arranging a plurality of key contacts SW11, SW12, SW21, SW22, . . . at cross points of a key matrix is provided with a power supply control key (SW11), and a key scan circuit 101 for detecting open/close states of the plural key contacts of the key switch 102 is independently arranged from a power supply control key state detecting means for detecting the open/close state of the contact SW11 of the power supply control key. The depression of the power supply control key (SW11) is detected by the power supply control key state detecting means. When the operation is ended, or the power supply is turned OFF, the depression of the power supply control key is detected by the key scan circuit 101, and the supply of the electric power is stopped.

Abstract: An improved key matrix scanning technique conducts a first pre-scan on a first array of connections in a key matrix to identify any activated keys or buttons associated with the first array. A second sub-scan is conducted on a second array of connections in the key matrix but only for the connections in the first array that are detected as having activated keys.

Abstract: An unpartitioned high-speed 8B/10B encoder and corresponding methods use only one edge or level of the clock signal per clock cycle to encode a set of 8B to a corresponding set of 10B data, and thus is not limited to a 50% clock duty cycle. The encoder includes an unpartitioned encoding circuit that receives 8B data and a special character signal and generates 10B intermediate data, a disparity control that receives the 8B data and the special character sign in parallel with that information being received by the encoding circuit, and also receives a clock signal, and generates two control signals; and logic circuitry that receives the intermediate output data and the two control signals and generates the 10B output data. The encoder may be embodied in a high-speed encoding system in which the processing speed of the encoder is greater than 250 MHz.

Abstract: A communications channel includes a buffer that receives user data symbols including a plurality of M-bit symbols. A seed selector receives the plurality of M-bit symbols, selectively removes symbols from a seed set based on Hamming distances between at least two of the M-bit symbols, and selects a scrambling seed from remaining symbols in the seed set. A scrambling device that communicates with the seed selector and the data buffer generates scrambled user data based on the user data symbols and the scrambling seed. The communications channel is implemented in a data storage system. The seed selector ensures a minimum Hamming weight of 15 percent in the scrambled user data. The seed selector compares first and second user data symbols in the plurality of M-bit symbols.

Abstract: A code sequence is encoded using a code conversion table in which the parity of the code sequence varies until the code states become equal to each other. The code word assignment used in this code conversion table is such that the decoded code word constraint length is 3 blocks and q0?q1 for an arbitrary information sequence is satisfied even if a DC control bit is inserted at any of the first and second bits of an information word. Code states s0 and s1 when information sequences d0 and d1 resulted from insertion of provisional DC control bits 1 and 0 inserted at the top of an information sequence “1, 1, 0, 0, 0, 1, 0” are encoded starting with a state 3 according to a predetermined code conversion table are equal to each other, namely, s0=s1=6, in a third block, and two's complement q0 of a sum of code sequences c0 up to a time when the code states are equal to each other is “0,” while two's complement q1 of a sum of code sequences c1 up to that time is “1”. That is, the condition that q0?q1 is met.