Abstract: A multifrequency antenna comprising a stack of nonconductive substantially planar substrates, with a conductive layer disposed on each substrate surface. A first substrate includes transmission lines disposed on a rear surface and a conducting layer on the other surface. A second substrate is stacked on the first substrate. A conducting layer is disposed on one side of the second substrate surface. Conducting layers disposed on first and second substrates include a plurality of slotted openings arrayed about an antenna axis. A third substrate stacked on the second substrate includes a conducting layer top. A lossy dielectric-magnetic material encloses sides and rear of the multifrequency antenna, to prevent electromagnetic energy penetration through the enclosure. An edge diffraction suppresser reflector is attached in the rear surface of the multifrequency antenna, and has two or more essentially circular, conducting plates and a multitude of conducting cylinders along the axis of the multifrequency antenna.

Abstract: Protecting content from piracy. A user computer stores a stored address. A smart card stores a smart-card address. The smart-card address matches the stored address. A seller stores content to be sold to the user. The content is encoded using the smart-card address from the smart card, as encoded content. A header is added to the encoded content, to generate header-encoded content. The header-encoded content is written on an encoded disk. The user computer detects the header from header-encoded content, as a detected header. The smart-card address is read from the smart card and verified with the stored address at the user computer. In response to a match and to the detected header, the encoded content embedded in the header-encoded content is decoded from the encoded disk.

Abstract: A spread-spectrum system having a transmitted data rate determined by an error rate syndrome at a spread-spectrum receiver. Data are demultiplexed into a plurality of data channels, and spread-spectrum processed as a plurality of spread-spectrum channels. A combiner combines the plurality of spread-spectrum channels as a code-division-multiplexed signal. At a receiver, the code-division-multiplexed signal is despread into a plurality of despread channels. A multiplicity of adders, which is electronically controlled by an adder-control signal, adds several of the despread channels to generate a multiplicity of added channels. A syndrome signal is generated from an error rate of the multiplicity of added channels. From the syndrome signal, a desired-data rate is determined for the spread-spectrum transmitter.

Abstract: A system and method for transmitting a plurality of spread-spectrum signals over a communications channel having fading. The plurality of spread-spectrum signals are radiated by a plurality of antennas, with each antenna preferably spaced by one-quarter wavelength. A plurality of receiver antennas receive the plurality of spread-spectrum signals and a plurality of fading spread-spectrum signals. Each receiver antenna is coupled to a plurality of matched filters having a respective plurality of impulse responses matched to the chip-sequence signals of the plurality of spread-spectrum signals. A RAKE and space-diversity combiner combines, for each respective chip-sequence signal, a respective plurality of detected spread-spectrum signals and a respective multiplicity of detected-multipath-spread-spectrum signals, to generate a plurality of combined signals. The symbol amplitudes can be measured and erasure decoding employed to improve performance.

Abstract: An improvement to a spread-spectrum receiver having a matched filter. A symbol sampler samples at the symbol time TS, a symbol sample from the matched filter. A noise sampler samples at a plurality of chip times kTC, but not at the symbol time TS, a plurality of noise samples from the matched filter. An estimator or low-pass filter estimates the plurality of noise samples from the symbol sampler, to generate a noise estimate. A combiner subtracts the noise estimate from the symbol sample, thereby generating a comparison signal. A magnitude device determines a magnitude of the comparison signal. A comparator compares the magnitude of the comparison signal to the threshold voltage, thereby generating the erasure signal. An erasure decoder erasure decodes the input data using the erasure signals from the erasure detector.

Abstract: An improvement to a spread-spectrum code-division-multiple-access system, using a channel sounding signal from a base station (BS) to provide initial transmitter power levels for remote stations (RS). The base station transmits BS-spread-spectrum signals at a first frequency and receives RS-spread-spectrum signals, which are transmitted by the remote stations at the second frequency. The base station transmits a BS-channel-sounding signal at the same carrier frequency being used by the remote stations. The bandwidth of the BS-channel-sounding signal is much less than the bandwidth of the BS-channel-spread-spectrum signal. Each remote station tracks the BS-channel-sounding signal, for adjusting the initial RS-power level.

Abstract: A high data rate, high processing gain, direct sequence spread spectrum system that transmits a BPSK or QPSK signal. The data which are collected and stored and forwarded N bits at a time by transmitting one of 2N pseudo random waveforms every time N bits are collected. During acquisition, product devices multiply a received spread-spectrum signal by a header chip-sequence signal. After acquisition, the product device multiply the received spread-spectrum signal by 2N chip-sequence signals to generate products, with each chip-sequence signal of the chip-sequences signals being different from other chip-sequence signals of the chip-sequence signals. Integrators integrate the products thereby forming 2N correlators, and a comparator selects a largest value from the integrators. The largest value is decoded into N bits of data.

Abstract: A multilevel computer security system including a computer with multiple security subsystems for secure data storage and data communications at each security level, a smart-card reader for controlling user access to each security level, and an electronically-activated switch for activating only the selected and authorized security level. Access to each level of restricted data requires a user to insert his smart card into a smart-card reader. The selection of an authorized level generates an activation signal, for a selected security level and permitted computer assets for the selected security level. Since only one security level is ever active and the switching from one level to another requires the computer RAM to be powered off, there can be no possibility of user access to unauthorized data.

Abstract: A transmitter and a receiver using a set of Large-Area Code-Division-Multiple-Access (LA-CDMA) codes. The LA-CDMA codes are generated from a plurality of pulses, and a plurality of codewords. The plurality of pulses has a plurality of intervals between each of the pulses. Each pulse has an amplitude and a polarity. Each interval is unequal to other intervals of the plurality of intervals. Only one interval is an odd number larger than a value of a smallest interval of the plurality of intervals. No value of any interval is a sum of any two or more values of two or more intervals, respectively, in the plurality of intervals. Each codeword is different from other codewords in the plurality of codewords. The plurality of codewords are either orthogonal, or bi-orthogonal, or trans-orthogonal.

Abstract: A multi-clock matched filter for receiving signals with multipath. The signals may be modulated with a spread-spectrum spreading sequence, or other analog or digital signal. A number of signal registers store digital samples of the received signal. The gating of digital samples into each of the signal registers is controlled by a separate clock timing. The timing sequence may be derived from a common clock. A multiplexer sequentially selects each of the signal registers, and passes the respective content of each signal register to a matched filter. A number of delay-locked-loop circuits track each of the multipath signals, and generate the timing sequence for gating signal registers.

Abstract: Quantum-size electronic devices comprise electrodes and at least one cluster seperated from the said electrodes by a tunnel-transparent gap. The characteristic dimensions for elements of quantum-size devices are determined by the formula in the range 1×4 r0, wherein r0=/(me&agr;2c), wherein is Planck's constant, me is the electron mass, &agr;=1/137,036 is the fine structure constant, c is the light speed. The cluster may be made of a semiconductor material, conductor, superconductor, high-molecular substance or a covering with a tunnel-transparent dielectric. The matured theory provides possibilities for designing logical devices operating in the mode of transfer and/or storing of several electrons at normal conditions and high temperatures. The operating conditions of the devices are determined.

Abstract: Controlling unauthorized access to software distributed to a user by a vendor. A verification key is generated by a product key generator and either embedded in the software prior to distribution or packaged with the software as a self-installing package. The verification key includes a public verification key. The combination of the software and the verification key create distributable software which is distributed to a user. The user installs the software on a user computer system as protected software. To obtain a user key, the user inputs identifying information, which may be for the user or for a group, which is sent to a user key generator. The user key generator converts the identifying information to a numeric representation and then generates, by signing the numeric representation with the private signing key, a user key, which is returned to the user.

Abstract: An improvement to a spread-spectrum receiver having a matched filter. A symbol sampler samples at the symbol time TS, a plurality of symbol samples from the matched filter. A relative-signal-level decoder decodes the plurality of received-symbol samples, generating a plurality of decoded-symbol samples. A noise sampler samples at a plurality of chip times kTC, but not at the symbol time TS, a plurality of noise samples from the matched filter, before, after, or a combination of before and after, a symbol sample. An erasure detector detects for each decoded-symbol sample from the plurality of decoded-symbol samples and from the plurality of noise samples, an erasure condition for the corresponding decoded-symbol sample, and generates an erasure signal. An erasure decoder erasure decodes the input data using the erasure signals from the erasure detector.