Abstract: An apparatus and method for proactively identifying and initiating corrective actions for restoration of a primary wireless data link during adverse operation conditions. The scheme imparts dynamic adaptability to the wireless link architecture and can ensure overall wireless link availability of better than 99.999%.

Abstract: A method and apparatus for information modulation for impulse radios are presented in both single-tone and pulse stream configurations. The modulation techniques include combinations of amplitude and phase modulation. The modulation techniques include both digital and analog schemes, including baseband on/off keying modulation, wavelet on/off keying modulation, pulse-position modulation, and FM modulation. Techniques for varying the modulation rate are also provided. Additionally, harmonics impulse ratio configurations are presented to take advantage of the modulation techniques.

Abstract: A method and apparatus for generating an arbitrary UWB waveform are presented. An optical comb generator generates a serial stream of optical tones and an optical beating tone. A serial-to-parallel converter receives the serial tones and converts them into parallel optical tones. A spatial light modulator receives the parallel optical tones, and independently adjusts at least one of the phase and amplitude of each to generate the components of an arbitrary waveform. Next, each one of a plurality of optical-to-electrical converters receives a parallel optical tone and the selected optical beating tone, which are beat with the optical beating tone, producing electrical notes, representing differences between each parallel optical tones and the optical beating tone. Each antenna element is connected to receive an electrical note and to launch a signal based thereon, such that the launched signals are superimposed to the arbitrary waveform signal.

Abstract: A method and apparatus for conditioning a wireless data communication path for the transmission of a signal wave are presented. The apparatus comprises a conditioning wave transmitter positioned to transmit a conditioning wave along at least a portion of the wireless data communication path. The conditioning wave forms a conditioning envelope about the data communication path. The wavelength of the conditioning wave is selected to remove undesirable particles from the wireless data communication path. As a result, the wireless data communication path is conditioned to provide for improved data communication. The conditioning wave may be transmitted co-, counter-, or bi-directionally with respect to the signal wave, and may form a second data channel.

Abstract: A wideband wireless access local loop system using millimeter wavelength wireless technology to provide wireless access to a series of customer interfaces, via a series of access interface points, to a backbone network of central nodes interconnected by a high transmission-rate broadband medium such as fiber optic cable. The network architecture is useful for providing a two-way high-speed data transfer system to structures without the need for physical wiring. Data transfer within the network may optionally be either analog or digital, and may be optimized for either two-way communication or one-way distribution.

Abstract: The present invention provides a megacell 100, which is divided into a plurality of picocells 102. Each picocell 102 is serviced by a secondary base repeater node configured to transmit to any of three adjacent picocells 102. The base station 106 acts both as an originating information signal source and as an originating base station for transmitting a command signal. The command signal is a narrowband signal, which can be transmitted on a channel with sufficient range to reach the entire megacell. The information signal is a broadband signal with a short range picocell, which is transmitted from a secondary base repeater node to its adjacent neighbors.

Abstract: An ultra-wideband beamformer is provided by using conventional phase shifting techniques to impress data and antenna scan information onto a narrow band signal. A non-linear element then converts the narrow sine wave into ultra-wideband pulses. Phase shift key modulation impresses data information onto the sine wave in the form of a phase shift. The data-bearing sine wave is split into multiple transmission lines where each provides an additional antenna scanning phase shift. The non-linear element converts each phase of the sine wave into short pulses which are sent to radiating elements for transmission. In the far-field of the beam, the scan delays between the radiating elements are canceled out, such that the fields from each radiating element are summed and the pulse position modulated data recovered.

Abstract: In a method and apparatus for converting optical wavelength division multiplexed channels to wireless channels, the information carrying optical carriers are first demultiplexed and each optical carrier is then extracted from the data using an optical channelizing technique. The optical frequency of each of the extracted optical carriers is then shifted by an amount equal to the desired wireless carrier frequencies in the broadband wireless channels. Optical heterodyning of the frequency-shifted extracted lightwave carriers with the original data-containing optical signals, which are mutually in phase coherence, in a photodetector results in a set of wireless carriers each modulated with the data carried by the corresponding optical channel.

Abstract: A system and method for linking optical wavelength division multiplexed (OWDM) networks by using wireless communications. Each optical channel in a OWDM network is coupled to a wireless wavelength division multiplexing (WWDM) channel by a WWDM transceiver, which transmits and receives data between OWDM networks. The WWDM transceiver may transmit and receive data in RF bands, where the assignment of different OWDM channels to different frequencies within the RF bands may depend upon the data rate or service supported by the OWDM channel. WWDM systems may also support communications between OWDM networks and individual users, such as those in a local multipoint distribution service.

Abstract: A front end module (10, 30) for a low weight, low power communications system. The front end module (10) utilizes RF microelectromechanical (MEM) switches (16, 18, 20, 110, 112, 156) for dynamic reconfiguration capability. Components (12, 14, 22, 24, 26, 28) are shared for both the transmit and receive modes, thereby reducing the number of components required by the system (10, 30).

Abstract: A hybrid wireless link 100 of the present invention provides a gateway between two wired data systems 102, such as backbone fiber networks, and comprises a laser portion 104, a radio frequency portion 106, and a controller 108. The laser portion 104 and the radio frequency portion 106 provide, side-by-side and point-to-point, a free-space optical wireless link and a radio frequency wireless link. The controller 108 may be designed to respond to atmospheric conditions based on environmental information such as weather tables or the transmit/receive power of the laser portion 104 and the radio frequency portion 106, with signal switched between the laser portion 104 and the radio frequency portion 106 with a binary switch or a variety of latched levels using an incremental switch. The hybrid wireless link 100 may also use multiple channels and may be configured for a variety of networks including multi-channel ring topologies.

Abstract: Techniques and architecture as well as channel multiplexing schemes to design and implement multi-megabit and gigabit transfer of data in situations requiring or optimized by wireless communication systems are presented as a method by which the high-speed signal integrity of a transmission may be maintained over a hostile wireless link and by which a high-speed transmission may be made while maintaining a bit-rate below the delay spread value such that the unforgiving propagation conditions normally associated with high-speed transfer are mitigated. The system is adaptable to any use where a multi-megabit and gigabit wireless link is desirable; for example in office buildings lacking fiber infrastructure, in rapid deployment situations such as those required in military or emergency situations, or where other separate broadband infrastructures do not exist to the end users for integrated telephone, Internet, and digital data systems.

Abstract: An optical monitor tap in fiber optical amplifiers is achieved in a configuration with internal input signal monitoring taps, in accordance with the principles of the invention, by placing the tap some distance into the actual optical amplifier active fiber. This allows the system to minor the integrity of the amplifier without impairing the quality of the associated signal. In an illustrative embodiment of the present invention, the amplifier is generally comprised of a long piece of rare-earth material doped fiber to which a fiber optic pump source is coupled via a wavelength divisional multiplexer (WDM) coupler. The tap is placed at some distance from the input of the fiber amplifier. The distance should be small enough such that there has been amplification of the signal but not so much as to have the signal saturated or compressed.

Abstract: Recovery of the timing signal is obtained directly at the receiver of the time-division multiplexed transmission system in accordance with the present invention. At the transmitter, multiplexing (203) of plural return-to-zero format (RZ) channels (201-1-201-N) is delay controlled (202) so that the position of each pulse of each channel within each time slot is offset from the beginning or the end of the time slot by a predetermined fixed delay, the position of the data bits in pairs of adjacent time slots being mirror-imaged with respect to their common time point. The power density spectrum of the resultant signal has an "enchanced" discrete component at the clock frequency and a dip in the continuous spectrum. At the receiver a large amplitude phase-synchronized clock signal is derived from this discrete component in one single step by an injection-locking technique (704).

Abstract: A diode laser amplifier used as a clocked optical regenerator and other diode laser amplifier optoelectronic functional circuits are disclosed. In the regenerator circuit (101), the input optical pulse data signal to be regenerated is inputed to a diode laser amplifier (102), the gain of which is modulated by a clock signal electronically recovered from and synchronized with the input data signal. By modulating the gain so that it is substantially attenuated during essentially half of each bit interval, and at a high gain level during the other half of the bit interval, each pulse in the input signal is both amplified and "cleaned up" produce an output pulse signal that is an amplified, reshaped and retimed version of the input optical signal.

Abstract: A short optical pulse generator is disclosed in which the optical radiation from a driven laser diode (101) is coupled to an external cavity which includes a looped directional coupler (104, 120) which reflects a portion of the optical radiation back to the laser causing the laser to mode-lock and produce an output which consists of a stream of very short high repetition optical pulses. By changing the length of the loop (107), the repetition rate of the pulse stream can be varied and by adjusting the coupling coefficient of the coupler either mechanically or electrooptically, the pulse width and pulse height parameters of the pulse stream can be varied.

Abstract: A semiconductor laser diode which operates in an extended optical cavity in conjunction with a negative resistance device such as a Gunn diode for sustained mode-locked operation. The circuit is capable of generating high repetition rate picosecond optical pulses and is suitable for monolithic or hybrid implementation.