Frequency translation and applications of same are described herein, including wireless local area network (WLAN) applications such as IEEE Standard 802.11 WLANs. Such applications include, but are not limited to, frequency down-conversion, frequency up-conversion, enhanced signal reception, unified down-conversion and filtering, and combinations and applications of same.

Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation

Methods for down converting a modulated carrier signal to a demodulated baseband signal are described herein The method requires that a first portion of energy is transferred from the modulated carrier signal, and stored at a first storage device when a first switch is on At least some of the energy stored in the first storage device is discharged when the first switch is off The method further comprises transferring a second portion of energy from the modulated carrier signal, storing at a second storage device the second portion of transferred energy when a second switch is on, and discharging at least some of the energy stored in the second storage device when the second switch is off A down-converted in-phase baseband signal portion is generated from the energy accumulated in the first storage device while both the charging and the discharging occurs, and a down-converted inverted in-phase baseband signal portion is generated from the energy accumulated in the second storage device while both the charging and the discharging occurs, and the two portions are combined with a first differential amplifier circuit to form a down-converted differential in-phase baseband signal

Method and system for down-converting an electromagnetic signal

Apparatuses, methods, and systems are disclosed for controlling optical signal wavelength spacing by providing for simultaneous upconversion of a plurality of electrical signal on subcarrier frequencies of an optical carrier frequency with or without modulation of an electrical data signal onto the optical carrier frequency. The optical carrier lightwave is split into a plurality of split lightwaves upon which one or more electrical frequencies carrying information can be upconverted onto optical subcarriers of the lightwave carrier frequency. The relative spacings of the optical subcarrier lightwaves will thus be unaffected by variation in the carrier frequency. The optical subcarrier lightwaves can then be recombined to form the optical data signal carrying the plurality of information carried by the electrical frequencies.

Optical Transmission apparatuses, methods, and systems

Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting and up-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal. Up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency.

Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same

The present invention includes a system and method for ensuring reception of a communications signal. A modulating baseband signal with desired information is accepted, and a plurality of redundant spectrums is generated. Each redundant spectrum comprises the necessary amplitude, phase, and frequency information to substantially reconstruct the modulating baseband signal. It is expected but not required that the redundant spectrums will be generated at a first location and sent to a second location over a communications medium. At the second location, the redundant spectrums are independently processed to recover a demodulating baseband signal for each of the redundant spectrums. In one embodiment, an error detection process is employed at the second location to detect and eliminate those demodulated baseband signals that have been corrupted during transmission. An error-free demodulated baseband signal is selected from the remaining demodulated baseband signals. The error-free demodulated baseband signal is representative of the modulating baseband signal sent over the communications medium.

Method and system for ensuring reception of a communications signal

An optical beam having a high radio-frequency modulation is generated at output (10) by generating in source (4a) a lower frequency modulation, using it to control the optical output (3) of a laser (1) and further modulating the optical output (3) in an optical modulator (6) by a control signal having another lower frequency modulation generated by source (4b). Either or both of the lower frequency modulations also carries an information containing modulation. The effect of the optical modulator (6) is to up-convert the modulation carried by the optical beam by the modulation frequency of the control signal. The optical modulator (6) may be a Mach-Zehnder interferometer. The non-linearity of such a modulator with respect to its control input may be exploited by selecting the amplitude of the control signal such that the optical output (3) is upconverted by an integer multiple of the modulation frequency generated by source (4b). These methods avoid the need to apply the high frequency modulation to either the laser input (2) or the control input directly (7).

Ian Christopher Smith

Papers

Generation of optical signals with rf components