Abstract: Compact bidirectional repeaters are provided for wireless communication systems. Their compact size is realized with repeater structures that include different-polarization antennas, back lobe suppressing structures, circuit feedback paths, antenna-feedback detectors, and automatic gain control.

Abstract: The present invention provides for inexpensive transparent microwave antennas with high efficiency. Conductors for the antennas are formed from metallic meshes with a net transparency greater than 70% and supported by a clear substrate. The associated antenna gain efficiencies are greater than 50%.

Abstract: Local-oscillator systems for wireless communication systems are realized with oscillator networks that are phase locked to a bit timing clock. Two of the networks provide first and second phase coherent local-oscillator signals respectively to a receiver and transmitter of a transceiver. A third oscillator system forms a phase lock loop about one of the other networks and preferably includes a crystal to enhance short term stability. Because they track the bit timing clock, the first and second local-oscillator signals phase track all communication signals in the transceiver's communication system.

Abstract: Methods and systems are provided for spectrally separating first and second satellite signals that occupy a common frequency band with different first and second electromagnetic polarizations. These systems and methods facilitate the use of inexpensive single-cable distribution networks to simultaneously deliver all transmitted channels of a satellite communication system to a plurality of subscriber locations. In particular, a frequency-converter system is provided that includes first and second low-noise block downconverters whose outputs are coupled into an output diplexer. The low-noise block downconverters each have a downconverter mixer and a local oscillator that couples a local oscillator signal to the mixer but the local oscillator signals are sufficiently spaced apart to convert the first and second satellite signals to spectrally spaced first and second intermediate-frequency (IF) bands. The IF bands are isolated because they are spectrally separated.

Abstract: Receiver systems and methods are provided for processing transmit signals Str that are received over a receive channel Crcv which is formed by a plurality of receive paths. Method embodiments comprise the steps of a) receiving the transmit signals Str with a plurality of spatially separated antennas to form respective receive signals Srcv, and b) spatially and temporally processing the receive signals Srcv to form a combined corrected signal Scrctcmb that reduces errors in at least one signal parameter. Exemplary signal parameters include signal preambles, codes, spreading codes and modulations.

Abstract: Wireless communication methods and structures are provided that enhance communication robustness while reducing cost. They communicate downstream data with orthogonal frequency division multiplexing (OFDM) transmission processes and upstream data with single carrier transmission processes. This combination of transmission processes is configured with various signal modulations (e.g., quadrature phase shift keying (QPSK), m-ary phase shift keying (MPSK) and n-quadrature amplitude modulation (QAM)) to provide lower cost upstream communication from customer services equipments (CPEs) and more robust downstream communication from headends than has been achieved in conventional communication systems. Signal diversity is enhanced by receiving communication signals with multiple antennas that are spatially separated and have different polarizations to thereby enhance frequency diversity.

Abstract: Muting systems and methods are described that reduce noise signals that are received in a communication hub which communicates with indoor units (IDUs) of a plurality of communication customers. The systems and methods reduce transmitter signal gain when uplink communication signals to the transmitter input port are less than a predetermined threshold. Accordingly, accumulated noise signals at the communication hub are reduced and the system performance of the communication hub is not degraded.

Abstract: Packet-based communication methods and systems are provided which improve data throughput and which respond to different error-rate conditions with modifications appropriate for those conditions. In method embodiments, data frames are initially formed to each have N data packets and a frame error code. Data frames are then transmitted and checked. In response to the check, data packets of error-free data frames are routed through the system and data frames that are in error are retransmitted. The checking, processing and retransmitting steps are repeated until all data packets are routed through the communication system. In another method embodiment, data packets of each data frame found to be in error in the checking step are inserted into a data frame of the forming step. In a feedback feature, a system error rate is determined and, in response, N is periodically updated to a value that realizes the best throughput under the current noise condition of the transmission link.

Abstract: Wireless communication methods and structures are provided that enhance communication robustness while reducing cost. They communicate downstream data with orthogonal frequency division multiplexing (OFDM) transmission processes and upstream data with single carrier transmission processes. This combination of transmission processes is configured with various signal modulations (e.g., quadrature phase shift keying (QPSK), m-ary phase shift keying (MPSK) and n-quadrature amplitude modulation (QAM)) to provide lower cost upstream communication from customer services equipments (CPEs) and more robust downstream communication from headends than has been achieved in conventional communication systems. Signal diversity is enhanced by receiving communication signals with multiple antennas that are spatially separated and have different polarizations to thereby enhance frequency diversity.

Abstract: Full-duplex, coherent transceivers are provided which can directly interface between exisiting data interface modules (e.g., cable modems) and wireless cable providers to facilitate the flow of high-speed downlink communication signals and high-speed uplink data signals. Currently, a speed bottleneck is formed between consumers and various communication resources (e.g., the internet) by low transfer rates of telephones and conventional modems. This bottleneck is removed by transceivers of the invention. The transceiver structure prevents frequency inversion and reduces cost because it can form the required interface without requiring additional interface modules.

Abstract: Paraboloidal grid reflectors and antennas are provided which are lighter and have less wind loading because they efficiently realize selected front-to-back ratios by recognizing the angular distribution in typical differential path losses and feed gains. In particular, the reflectors are formed with adjacent pairs of parallel elongate members that are positioned at respective angles &thgr; from the paraboloidal vertex and spaced apart by respective spaces S that generally increase with increased angle &thgr;. In some reflector embodiments, the spaces S increase with increased angle &thgr; for a contiguous majority of adjacent pairs and may be constant for a contiguous minority that typically adjoins the vertex. In other reflector embodiments, the spaces S increase with increased angle &thgr; for all of the adjacent pairs.

Abstract: Antenna structures are shown that reduce fabrication and assembly time and cost, increase antenna reliability and enhance antenna performance. These structures include resilient flanges that are formed by a slotted ground plane and a rear ground plane which together surround a feed circuit. The ground planes are simply pressed together to engage the flanges in an overlapped and resiliently interlocked relationship. In other antenna structure, a capacitance probe forms a part of a coaxial transition. One end of the probe forms a capacitance face and the transition is configured to automatically space the capacitance face from a trunk end of the feed circuit. A second end of the probe is available for coupling signals to antenna-associated circuits (e.g., a downconverter). A pressed-together signal-transmission path through these circuits is formed with spring-loaded sockets. One socket receives the capacitance probe's second end and the other receives the center pin of an external coaxial connector.

Abstract: Interface modules are disclosed that can couple combined signals in communication signal bands (e.g., cable television and upper and lower direct broadcast satellite signal bands) to communication receivers (e.g., integrated receiver decoders). These modules facilitate the use of inexpensive single-cable distribution systems in multiuser facilities (e.g., apartment and office buildings).

Abstract: An end-fire array antenna achieves improved performance with an array of radiative members that are arranged collinearly between an array first end and an array second end and a divergent reflector which is arranged collinearly with the radiative members. The radiative members are spaced to facilitate radiation and reception of electromagnetic signals in an antenna direction which extends from the array second end and the divergent reflector is spaced from the array first end to enhance this radiation and reception. A wall of the reflector preferably diverges from an antenna axis by an angle in the region of 24 to 48 degrees. The divergent reflector terminates in an open end which has a transverse width that preferably exceeds 1.4 .lambda..sub.dsgn wherein .lambda..sub.dsgn is the design wavelength of the antenna. In-service antennas are modified with a divergent reflector that is configured for coupling to an existing antenna back wall or antenna cup.

Abstract: An antenna/downconverter directed to the subscription television distribution industry having low cross polarization and broad bandwidth. The antenna/downconverter includes a director mounted to a housing which defines a reflector cup, side lobe suppression rim and a housing defining a chamber which provides environmental protection for downconverter electronics. Received microwave energy is coupled to the downconverter electronics from a point radially inward from the perimeter of a first receive disc axially spaced within the reflector cup using a probe surrounded by a conductive probe shield integral to the reflector cup. A second receive disc having a different radius than the first receive disc and axially spaced within the reflector cup is parasitically coupled to the first probe. The second receive disc additionally includes wings coupled to the perimeter of the reflector cup for shunting cross-polarized microwave signals.

Abstract: An antenna/amplifier includes a waveguide and an amplifier system. The amplifier and signal lines which terminate in orthogonal probes are carried on a common substrate. The orthogonal probes are spaced from a waveguide wall and isolated for good cross polarization by a post which extends from the wall. The probes have probe tips which are spaced from the post by a probe space. Parameters which include the probe space, the impedance of the signal lines and the length of the signal lines can be selected to present an optimum impedance to low-noise amplifiers of the amplifier system.

Abstract: An decryption system which facilitates simultaneous decryption of multiple encrypted television channel signals thus making them simultaneously available for direct tuning in television receivers. The system is characterized by the utilization of a plurality of channel signals time synchronized with respect to a common timing reference signal. Each channel signal is encrypted in accordance with a predetermined encoding rule and distributed to subscriber sites where an unencrypted block of channel signals are made simultaneously available by decrypting them synchronously with the recovered timing reference signal in accordance with the inverse of the encoding rule. An interdiction apparatus then selectively jams a plurality of television channels from within the unencrypted block of channel signals thus making it possible for a provider to programmably interdict reception of selective channels by unauthorized subscribers.

Abstract: An antenna suitable for use at subscriber sites in a television distribution system having a high front-to-back ratio and optimized for reception within multiple frequency bands. The antenna is comprised of multiple tapered antenna stages including a primary antenna stage for receiving a primary frequency band and a coupling antenna stage for matching the impedance of the primary antenna stage to either a coaxial cable or downconverter electronics. The multiple antenna stages are alternatively formed from either a stamping of a metal sheet or a double sided printed circuit board.

Abstract: An encryption/decryption system which facilitates simultaneous decryption of multiple encrypted television signals thus making them simultaneously available for direct tuning in television receivers. The system is characterized by the utilization of a plurality of channel signals each containing picture portions and synchronization portions respectively corresponding to the picture components and synchronization components of a different video signal. Corresponding portions of all channel signals are time synchronized with respect to a common timing reference signal. Each channel signal is encrypted in accordance with a predetermined encoding rule and distributed to subscriber sites where the channel signals are made simultaneously available for viewing by decrypting them synchronously with the recovered timing reference signal in accordance with the inverse of the encoding rule.