Stateof polarization encoding for optical code division multipleaccess networks. In telecommunications, orthogonal frequencydivision multiplexing ofdm is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. In the transmitter, there is a softwaredefined user code generator and a payload data modulator. In classical physics, light is modeled as a sinusoidal electromagnetic wave in which an oscillating electric field and. Figure 1 shows the basic architecture of the proposed ocdma system, which consists of a transmitter and receiver. The polarization state is elliptical for all other values of. Ofdm has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, dsl internet.
Dec 11, 2014 it isusually combined with other multiplexing techniques to better utilize the individual physical channels. We propose a novel multiple access and modulation scheme polarization division multiple access pdma and polarization modulation pm using polarization which is theoretically different from the abovementioned polar modulation for short range wireless communications, and the. Aug 25, 2011 in this paper, we take a new angle of view at the application of polarization for wireless communications. Request pdf stateof polarization encoding for optical code division multipleaccess networks in this paper we propose the use of the state of polarization sop encoding in order to realize. Us5515378a spatial division multiple access wireless. It comes from the greek word polos, for the axis of a spinning globe. This paper proposes a theoretical study to characterize the transmission of optical code division multiple access cdma systems deploying polarization shift keying polsk over a free space optical fso link under the impact of atmospheric turbulence. Principle of polarization shift key optical code division multiple access. Imt2000 is proposed to be the third generation standard and will use either a wideband cdma or tdma technology. Scm based passive optical networks pons enable multiple users to share.
Code division multiple access cdma code division multiple access technique is an example of multiple access where several transmitters use a single channel to send information simultaneously. Polarization tutorial let e1 be initially polarized along x, and let the waveplate slow axis make an angle. Field guide to polarization 2005 collett publications. Communications via satellites have two unique charac. The poincare sphere is used to describe the polarization and changes in polarization of a propagating electromagnetic wave. Any polarization state of light at any spatial position behind the scattering medium can be attained with this technique. Polarizationdivision multiple access pdma is a channel access method used in some cellular networks. Fundamentals of communications access technologies. This paper focuses on the capacity of polarization division multiple access pdma channel to propose an optimal pdma power allocation scheme that refers. Polarization division multiple access pdma is a method to simultaneously transmit two independent signals by using vertical and horizontal.
Antenna diversity and polarization antenna diversity scheme devised to compensate multipath effects by using multiple antennas the incoming rf signal is received through one antenna at a time. Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectraamplitudecodingbased optical code division multiple access sacocdma system. This is the classical access method used in ethernet localarea networks lans. Using measurements from an array of receiving antennas at the base station, parameters of multiple signals transmitted to the base station from a plurality of users in the same channel are calculated and used to obtain the positions and. Types of polarization plane of polarization light is an electromagnetic wave, i. Polarization division multiple access pdma is a channel access method used in some cellular networks. Setting the frequency difference between two polarization orthogonal reference carriers as one subcarrier spacing, possible signal fading can be. Tutorial fiber basics optical fibers are circular dielectric waveguides that can transport optical energy and information. Wireless communication multiple access tutorialspoint.
Scribd is the worlds largest social reading and publishing site. When cdm is used to allow multiple users to share a single communications channel, the technology is called code division multiple access cdma. Figure 1b shows an example of two orthogonal sop represented in the poincare sphere. A coordinated transmission method in a beam division multiple access environment dividing a service target region into a plurality of beam sectors through a plurality of antenna arrays having at least one of a pattern characteristic and a polarization characteristic, the method comprising. Wideband code division multiple access wcdma tutorial. December 2009 learn how and when to remove this template message. Polarization coordinates polarization table 1 shows the theoretical ratio of po wer transmitted between antennas of different polarization.
Interference can be near zero, even if mobile stations use the same allocated frequencies. One unique variation of sdma, polarization division multiple access pdma, separates signals by using different polarizations of the antennas. Polarization division multiple access with polarization modulation for. Elevation beamforming with full dimension mimo architectures. Polarization of light introduction light, viewed classically, is a transverse electromagnetic wave.
The present invention is related to a beam division multiple access system and a method thereof. The receiving radio constantly samples the incoming signals from both the antennas to. Modulation techniques bpsk binary phase shift keying qpsk quadriphased phase shift keying. Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectraamplitudecodingbased optical codedivision multipleaccess sacocdma system. It will be shown that the polarization of a general multiple access channel with a pointtopoint channel can be given a more achievable rate region in the general form. We show that the polarization state of coherent light propagating through an optically thick multiple scattering medium can be controlled by wavefront shaping, that is, by controlling only the spatial phase of the incoming field with a spatial light modulator. Implementation of polarization matching technique for polarization. Separate antennas are used in this type, each with different polarization and followed by separate receivers, allowing simultaneous regional access of satellites.
There are many multiple access techniques evolved for sharing the common resources among multiple subscribers or users or clients. Multiple access protocols connectionless scheduling contention random access cdma. The vectors e and h of the electric and magnetic fields of the tranverse electromagnetic tem wave are perpendicular to one another and orthogonal to the direction of light energy. Polarizationdivision multiplexed pdm transmission based on the nonlinear fourier transform nft is. Osa polarization control of multiply scattered light. Code division multiplexing cdm is a networking technique in which multiple data signals are combined for simultaneous transmission over a common frequency band. We propose a novel multiple access and modulation scheme polarization division multiple access pdma and polarization modulation pm using polarization which is theoretically different from the abovementioned polar modulation for short range wireless communications, and. Polarization division or dual polarization frequency reuse. If the vector appears to rotate with time, then the wave is elliptically polarized. Polarization is a property that is common to all types of vector waves. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference mai and the system performance will be. This technology supports multiple connections on a single conventional channel where different users are identied by spatial signatures.
In the transmitter, there is a softwaredefined user code generator and a. Classification of multiple accesses and their protocols is shown in fig. Circular polarization and polarization losses by rastislav galuscak om6aa, pavel hazdra1. Polarization division multiple access article about. A study of dispersion compensation of polarization. When cdm is used to allow multiple users to share a single communications channel, the technology is. It is shown by means of a new receiver model that the normally disturbing statistical fluctuations of the state of polarization on a singlemode fiber result in an attenuation of the. The duplex technology can be frequency or time division duplex synchronized or non synchronized. For light electromagnetic waves the vectors are the electric and magnetic. Us20100165914a1 beam division multiple access system and. Top 124 sdma spatial division multiple access things you. Performance of a parabolic dish antenna for cp to gain a better understanding of polarization losses, the polarization characteristics of a parabolic dish antenna with 0. In our analysis, a novel transceiver architecture for atmospheric ocdma fso systems based on polarization modulation with direct detection is.
In this paper, we discuss a potential multiple access and modulation scheme based on polarized states ps of electromagnetic em waves for. Its technology divides a signal into different timeslots, and increases the data carrying capacity. For each of these elements, we discuss how their design is impacted by mmwave radio propagation characteristics and present enabling mechanisms defined in. Use past spacedivision multiple access goals and revise understanding of spacedivision multiple access architectures. For light electromagnetic waves the vectors are the electric and magnetic fields, and the lights polarization direction is by. If the orientation of e q in fig 1 remains fixed as the wave moves forward, the light is planepolarized. The polarization of an electromagnetic wave is defined as the orientation of its electric field vector. Polarization division multiple access with polarization. Dielectrics in electric fields polarization vector the polarization vector is a vector such that. Polarization tutorial rocky mountain instrument co. These ratios are seldom fully achieved due to e ffects such as reflection, refraction, and other wave interactions, so some practical ratios are also included. Separate antennas are used in this type, each with different polarization and followed by separate receivers, allowing simultaneous regional access of satellites each corresponding ground station antenna needs to be polarized in the same way as its counterpart in the satellite. Ofdm has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, dsl internet access, wireless networks, power line networks, and 4g.
Osa pmd tolerant directdetection polarization division. Polarizationdivision multiple access pdma is a channel access method used in some. Optical code division multiple access secure communications. Wavelength division multiple access wdma is a related to fdma. Polarization division multiplexing pdm is a physical layer method for multiplexing signals carried on electromagnetic waves, allowing two channels of information to be transmitted on the same carrier frequency by using waves of two orthogonal polarization states. Polarization division multiple access pdma systems 4 6.
In this paper, we discuss a potential multiple access and modulation scheme. Performance evaluation of optical code division multiple. Stateofpolarization encoding for optical codedivision. Pressley maj james langley uk army dale white barry kruse shawn white ltc edward eidson thomas mims. Satellite communications architecture identify requirements. Frequency division multiple access tdma time division multiple access cdma code division multiple access. In addition, some other access schemes are usually used. When the waveplate is placed between parallel and perpendicular polarizers the transmissions are given by. Orthogonal frequencydivision multiplexing wikipedia.
Maximum ratio transmission for spacepolarization division multiple access in dualpolarized mimo system. Namely, the underlying oscillation in this case oscillating electric and magnetic elds is along directions perpendicular to the direction of propagation. Considering the applications of pf in radar and wireless communications for example 1723, the usage of polarization extends the available. Setting the frequency difference between two polarizationorthogonal reference carriers as one subcarrier spacing, possible signal fading can be. Mumimo 12 system is often considered in literature as an extension of spacedivision multiple access sdma. Improving the nonlinear tolerance of polarizationdivision multiplexed coofdm in longhaul fiber transmission. In cdma every user uses the full available spectrum instead of getting allotted by separate frequency. This is in contrast to longitudinal waves, such as sound waves.
Sep 01, 2015 principle of polarization shift key optical code division multiple access figure 1 shows the basic architecture of the proposed ocdma system, which consists of a transmitter and receiver. The base station according to the present invention comprises a initial mobile station information receiver for receiving initial mobile station information that a mobile station omnidirectionally transmits in an initial communication step, a mobile station location and speed detector for detecting. Fibers are typically made of silica with indexmodifying dopants such as geo 2. Polarization tutorial light, as the electromagnetic wave, is characterized by its power, wavelength frequency, phase and polarization state. Research open access polarization division multiple access. The receiving radio constantly samples the incoming signals from both the antennas to determine the higher quality signal. In this paper, we take a new angle of view at the application of polarization for wireless communications. Polarizationdivision multiplexing critical criteria. A description of the polarization of light to understand the polarization of light, we must first recognize that.
Pdma is also multiple access technique which separates the signals using different polarisation type of teh antenna. In this presentation suitable multiple access for future generations has been presented. The nature and mathematical formulation of unpolarized light and partially polarized light were not readily forthcoming until the 1950s, when questions about polarized light and the mathematical tools to deal with it began to be addressed in earnest. Maximum ratio transmission for space polarization division multiple access in dualpolarized mimo system. Army in transformation c4isrc2 architecture cpt corey s. Scmbased passive optical networks pons enable multiple users to share. This work proposes a novel directdetection polarization division multiplexed ofdm scheme without the need of dynamic polarization control at a polarizationdiverse receiver, and the proposed scheme is robust against polarization mode dispersion. Code division multiplexing cdm, code division multiple access cdma or spread spectrum is a class of techniques where several channels simultaneously share the same frequency spectrum, and this spectral bandwidth is much higher than the bit rate or symbol rate. A structured overview of digital communicationsa tutorialu.
Canvass polarizationdivision multiplexing visions and reinforce and communicate particularly sensitive polarizationdivision multiplexing decisions. The coordinated transmission method in a beam division multiple access environment, which divides a service target region into a plurality of beam sectors through a plurality of antenna arrays having at least one of a pattern characteristic and a polarization. Multiple access strategies fdma frequency division multiple access tdma time division multiple access cdma code division multiple access phase modulation plus pseudorandom noise. The present paper describes the advantages of the combination of optical code division multiple access and polarization shift keying direct detection. A coordinated transmission method based on beam division multiple access and an apparatus performing the same are disclosed. This work proposes a novel directdetection polarization division multiplexed ofdm scheme without the need of dynamic polarization control at a polarization diverse receiver, and the proposed scheme is robust against polarization mode dispersion. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference mai and the system performance will be degraded. They have a central core surrounded by a concentric cladding with slightly lower by. The paper begins by treating formatting, source coding, modulation, and potential tradeoffs for powerlimited systems and bandwidthlimited systems. The use of polarization division multiplexing pdm permits to multiply the. Polarizationdivision multiplexing polarizationdivision multiplexing pdm is a physical layer method for multiplexing signals carried on electromagnetic waves using the polarization of the.
Polarization division multiple access pdma using dualpolarized antennas in high xpd could increase data rate by almost double via vertically and horizontally polarized channels. It is used in microwave links such as satellite television downlinks to double the bandwidth by using two orthogonally polarized. Mar 12, 2010 duplex and multiple access technology the calculation of the composite interfering signal depends on the duplex and multiple access technology used in the radios. Jan 29, 2016 polarization division multiplexing polarization division multiplexing pdm is a physical layer method for multiplexing signals carried on electromagnetic waves using the polarization of the. The polarization of light is one of the most remarkable phenomena in nature and has led to numerous discoveries and applications.
Pdf polarization division multiple access with polarization. In conventional wireless communication systems, a base station serves many channels by means of different multiple access schemes, the most common being frequency division multiple access fdma, time division multiple access tdma, and more recently code division multiple access cdma. Polarization division multiplexing of ofdm radiooverfiber. Tech notes polarization tutorial light, as the electromagnetic wave, is characterized by its power, wavelength frequency, phase and polarization state. Any given polarization state corresponds to a unique point on the sphere. It isusually combined with other multiplexing techniques to better utilize the individual physical channels.
Time division multiple access tdma is a digital cellular telephone communication technology. It provides a convenient way of representing polarized light, and of predicting how any given retarder will change the polarization form. In telecommunications, orthogonal frequency division multiplexing ofdm is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. Polarizationdivision multiplexing based on the nonlinear. Sdma uses spatial multiplexing and enables for higher data rate. It facilitates many users to share the same frequency without interference. Duplex and multiple access technology the calculation of the composite interfering signal depends on the duplex and multiple access technology used in the radios. A unique and widely used method of multiple access is carrier sense multiple access with collision detection csmacd. Polarizationdivision multiplexing pdm is a physical layer method for multiplexing signals carried on electromagnetic waves, allowing two channels of information to be transmitted on the same carrier frequency by using waves of two orthogonal polarization states.
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