Patent us20070223938 – rate adjustable differential phase shift key (dpsk) modulation – google patentsuche
In a fixed delay optical communication system, rate adjustable differential phase shift key (DPSK) techniques eliminate the need for multiple comparing modules, each corresponding to a different data rate. Pulse width modulation ac motor speed control Setting alternative data rates at integer multiples of the fundamental data rate of the optical communication system allows the system to process the respective integer number of symbols per period of the system, wherein the period of the system is the inverse of the fundamental data rate. Pulse width modulation pic Pulse carving techniques may be used to set the duty cycle of clock levels associated with a clock signal. Pulse width modulation disadvantages The clock levels may be combined with respective symbols to provide optical symbols having a duty cycle less than 100%.
This specification discloses one or more embodiments that incorporate the features of this invention.
Pulse width modulation generator The embodiment(s) described, and references in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Pulse width modulation using 555 timer circuit diagram Moreover, such phrases are not necessarily referring to the same embodiment. Pulse width modulation for power converters principles and practice pdf Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
FIG. Pulse width modulation vfd 2 is a more detailed block diagram of the example rate adjustable DPSK communication system 100 shown in FIG. Definition of pulse width modulation 1. Pulse width modulation fan In FIG. Pulse width modulation animation 2, transmitter 102 includes a coherent light source 202, an optional pulse carving module 204, an encoder 206, a modulation driver 208, and a phase modulator 210. Pulse width modulation tutorial Coherent light source 202 provides coherent light. Pulse width modulation basics Pulse carving module 204 processes the coherent light to provide a plurality of clock levels, each having a duty cycle less than 100%. Pulse width modulation radiator fan controller Pulse carving module 204 is optional, depending on whether transmitter 102 implements a RZ-DPSK technique or a NRZ-DPSK technique. Pulse width modulation experiment For example, pulse carving module 204 is not necessary to implement a NRZ-DPSK technique, because a NRZ-DPSK symbol has a duty cycle of substantially 100%. Pulse width modulation matlab If a RZ-DPSK technique is used, then phase modulator 210 receives a first optical signal having a first phase from pulse carving module 204. Pulse width modulation led driver If a NRZ-DPSK technique is used, then phase modulator 210 receives the first optical signal having the first phase from coherent light source 202.
In FIG. Pulse width modulation dc motor 2, receiver 106 includes an amplifier 214, a band-pass filter (BPF) 216, a comparing module 218, a control circuit 220, a current meter 222, a difference node 224, a sum node 226, a first diode 228, a second diode 230, and a transimpedance amplifier 232. Advantages of sinusoidal pulse width modulation Amplifier 214 amplifies the optical communication signal received from transmitter 102. Pulse width modulation duty cycle BPF 216 filters out-of-band noise to provide a filtered optical signal. Pulse width modulation using 555 Comparing module 218 compares first and second non-adjacent symbols of the filtered optical signal. Pulse width modulation synth Comparing module includes multi-symbol delay module 108 b that provides the multi-symbol delay used by comparing module 218 to determine the temporal separation between the first and second symbols.
Referring to FIG. Pulse width modulator hho 2, comparing module 218 provides the sum of the first and second symbols to summing node 226 and the difference between the first and second symbols to difference node 224. Pulse width modulation and demodulation First diode 228 provides a first current signal based on the difference between the first and second symbols. Uses of pulse width modulation Second diode 230 provides a second current signal based on the sum of the first and second symbols. Pulse width modulation valve Transimpedance amplifier 232 receives a current signal that is substantially equal to the difference between the second current signal and the first current signal. Pulse width modulation vape Transimpedance amplifier 232 converts the received current signal to a voltage signal corresponding to the data signal processed by transmitter 102.
FIG. Sinusoidal pulse width modulation for 3 phase inverter 3 illustrates encoder 206 of FIG. Application of pulse width modulation 2 according to an example embodiment of the present invention. Pulse width modulation microcontroller In FIG. Sine pulse width modulation 3, encoder 206 includes a comparing module 304 and first multi-symbol delay module 108 a. Disadvantages of pulse width modulation Comparing module 304 has first and second input nodes 302 a- b, respectively. Pulse width modulation 555 timer Comparing module 304 provides as an output a first symbol at a first time instance t 0=0. Pulse width modulation and demodulation theory pdf First multi-symbol delay module 108 a delays the first symbol for a time period ?=m (i.e., a time period corresponding to m symbols) to provide a delayed symbol at second input node 302 b. Pulse width modulation heater control A data symbol is received at first input node 302 a. Pulse width modulation circuit design Comparing module 304 compares the delayed symbol and the data symbol to provide a second symbol in accordance with a DPSK technique at a second time instance t m=m. Pulse width modulation for power converters In an example, the first symbol corresponds with a first portion of an optical signal having a first phase and the second symbol corresponds with a second portion of the optical signal having a second phase.
Second multi-symbol delay module 108 b delays the first symbol for a time period ?=m and provides the first symbol to second node 402 b. Generation of pulse width modulation Fiber stretcher 404 piezo-electrically modulates the optical path length of the second path to stabilize comparing module 218. Pulse width modulation controller Fiber stretcher 404 provides the second symbol to second node 402 b. Pulse width modulation dc motor control Second node 402 b compares the first symbol and the second symbol in accordance with a DPSK technique to provide information. Variable pulse width modulation In an example, the information includes a sum of the first and second symbols and a difference between the first and second symbols. Pulse width modulation block diagram In another example, the first symbol corresponds with a first portion of an optical signal having a first phase and the second symbol corresponds with a second portion of the optical signal having a second phase.
FIG. Pulse width modulation motor 4B illustrates comparing module 218 of FIG. Pulse width modulation using 555 timer pdf 2 according to another embodiment of the present invention. Sinusoidal pulse width modulation theory In FIG. Pulse width modulation ppt presentation 4B, comparing module 218 is shown to be a differential group delay module for illustrative purposes. Pulse width modulation circuit diagram Referring to FIG. Pulse width modulation techniques pdf 4B, comparing module 218 includes respective first and second polarization controllers 406 a- b, second multi-symbol delay module 108 b, and a polarization beam splitter 408. Single pulse width modulation technique First polarization controller 406 a polarizes optical symbols 45° with reference to a principle axis. Pulse width modulation rectifier Second multi-symbol delay module 108 b horizontally and vertically polarizes each symbol, such that horizontal and vertical polarization states experience a differential delay. Pulse width modulation using 555 timer circuit The differential delay is based on the variable m associated with an m-symbol DPSK technique. Pulse width modulation explained For instance, the differential delay corresponds with an m-symbol delay. Pulse width modulation motor control Second polarization controller 406 b rotates symbols 45° that are received from second multi-symbol delay module 108 b. What is pulse width modulation tutorial Polarization beam splitter 408 interferes the respective horizontal and vertical polarization states to perform the m-symbol DPSK technique. Pulse width modulation voltage regulator For example, 406 a- b may reduce or eliminate thermal and/or acoustic induced phase wander.
Referring now to FIG. Pulse width modulation using 555 timer 11B, pulse carving module 204 is shown to include frequency divider 1102, modulation driver 1110, a phase modulator 1114, and a comparing module 1118. Pulse width modulation using 555 timer theory Frequency divider 1102 divides a frequency f of a clock signal by two to provide a divided clock signal having a second frequency
Modulation driver 1110 amplifies the divided clock signal. Pulse width modulation inverter circuit diagram Phase modulator 1114 combines the divided clock signal and the coherent light received from coherent light source 202 to provide an optical clock signal, having a plurality of optical clock levels. Pulse width modulation motor speed control Each optical clock level has a respective phase. Pulse width modulation stepper motor For instance, phase modulator 1114 may impress the divided clock signal upon the phase of the coherent light received from coherent light source 202 to provide the optical clock signal.
Embodiments of the invention may be implemented in hardware, firmware, software, or any combination thereof. Types of pulse width modulation Embodiments of the invention may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. Pulse width modulation advantages A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). Pulse width modulation and demodulation experiment theory For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Introduction to pulse width modulation Moreover, firmware, software, routines, instructions, etc. Pulse width modulation for power converters principles and practice ebook may be described herein as performing certain actions. Pulse width modulation dc motor speed control However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.
Example embodiments of the methods, systems, and components of the present invention have been described herein. Pulse width modulation dimmer As noted elsewhere, these example embodiments have been described for illustrative purposes only, and are not limiting. Pulse width modulation speed control of dc motors Other embodiments are possible and are covered by the invention. Pulse width modulation control theory Such other embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Pulse width modulation led Thus, the breadth and scope of the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.