1
Mohsen Kavehrad, Peter J McLane: Spread spectrum wireless PBX. AT&T Company and AT&T Bell Laboratories, David R Padnes, Erwin W Pfeifle, June 9, 1987: US04672658 (291 worldwide citation)

The present invention relates to a wireless PBX network wherein direct sequence spread spectrum multiple access is used for voice and data communications to support a plurality of local-local and local-external calls. The present wireless PBX arrangement comprises a plurality of local user transceiv ...


2
Isam M I Habbab, Mohsen Kavehrad, Carl Erik Sundberg: Packet switched interconnection protocols for a star configured optical lan. American Telephone and Telegraph Company AT&T Bell Laboratories, Erwin W Pfeifle, January 10, 1989: US04797879 (113 worldwide citation)

The present invention relates to packet switched interconnection protocols for use in high-speed optical Star-configured Local Area Networks (LANs). In the present Star LAN, a plurality of N+1 wavelength division multiplexed (WDM) channels are provided for use by M transceivers connected to the Star ...


3
Mohsen Kavehrad, Jack Salz: Combined cross polarization interference cancellation and intersymbol interference equalization for terrestrial digital radio systems. AT&T Company, AT&T Bell Laboratories, Patrick E Roberts, Robert O Nimtz, February 17, 1987: US04644562 (66 worldwide citation)

Data-aided equalization and cancellation in digital data transmission over dually polarized fading radio channels is disclosed. The present invention uses decision feedback structures with finite-tap transversal filters. Subject to the assumption that some past and/or future data symbols are correct ...


4
Mohsen Kavehrad, Carl Erik Sundberg: Collision detection technique for an optical passive star local area network using CSMA/CD. American Telephone and Telegraph Company AT&T Bell Laboratories, Erwin W Pfeifle, October 20, 1987: US04701909 (55 worldwide citation)

The present invention relates to a collision detection technique for an optical Star LAN using CSMA/CD. The present technique is implemented by preferably adding two or more fixed Hamming weight sequences, e.g., a fixed even or odd number of 1's in each unique cyclic error correcting code word, to t ...


5
Mohsen Kavehrad, Mansour I Irshid: Optical homodyne DPSK receiver with optical amplifier. The University of Ottawa, Spencer Frank & Schneider, January 19, 1993: US05181136 (44 worldwide citation)

An optical homodyne differential phase shift keying (DPSK) receiver for receiving and demodulating optical input signals, is provided with a power splitter for splitting the input signal into first and second signals, a delay is applied to the second signal, an optical amplifier optically amplifies ...


6
Mohsen Kavehrad: Cross-polarization interference cancellation arrangement for digital radio channels. AT&T Bell Laboratories, Erwin W Pfeifle, March 18, 1986: US04577330 (34 worldwide citation)

The present invention relates to a cross-polarization cancellation arrangement for digital radio channels wherein the cancellation arrangement comprises a canceller section and an equalizer section in cascade which operate at baseband. The canceller section includes both a main lobe estimator and de ...


7
Hyung B Kim, Farideh Khaleghi, Jinghui Li, Mohsen Kavehrad: Bidirectional optical amplifier. Northern Telecom, September 29, 1998: US05815308 (28 worldwide citation)

Bidirectional WDM transmission at 2.5 Gb/s using a bidirectional erbium-doped fiber amplifier (EDFA) is demonstrated over a distance of 300 km. A symmetrical EDFA configuration with a frequency tunable reflection attenuator is used as a bidirectional amplifier. Experimental results show that the all ...


8
Mohsen Kavehrad, Gang Yun: Optical interconnection device. University of Ottawa, Thomas Adams, November 21, 1995: US05469277 (9 worldwide citation)

In N.times.N optical couplers, such as are used in local area networks and backplanes of telecommunications and computer equipment, which use BRAGG volume diffraction means to couple light beams between the inputs and outputs, the number of gratings is reduced by means of so-called "grating degenera ...


9
Mohsen Kavehrad, Gang Yun: Optical taper for increasing the effective area of a photodiode in atmospheric free space communications applications. The University of Ottawa, Dennison Meserole Pollack & Scheiner, March 9, 1993: US05192863 (7 worldwide citation)

An optical receiver includes a photodiode having a surface area of suitable dimensions to permit reception of a signal at a high bit rate. Also, the optical receiver includes an optical taper having a head and a tail. The head is of greater diameter than the tail, and co-axial with the tail. The tai ...


10
Walter Debus Jr, Mohsen Kavehrad: Timing and carrier recovery in dual polarization communications systems. American Telephone and Telegraph Company, Bell Telephone Laboratories, David R Padnes, February 23, 1988: US04727534 (5 worldwide citation)

A technique is disclosed for improving the recovery of data signals transmitted on orthogonally polarized carrier signals by creating redundancy with respect to timing and carrier information. In the receiver, the carrier and timing recovery circuitry, which controls the recovery of the data signals ...