Thus, the balance detection scheme does not work perfectly to cancel multiple access interference mai and the system performance will be. The polarization of an electromagnetic wave is defined as the orientation of its electric field vector. In this paper, we discuss a potential multiple access and modulation scheme based on polarized states ps of electromagnetic em waves for. Mumimo 12 system is often considered in literature as an extension of spacedivision multiple access sdma. Modulation techniques bpsk binary phase shift keying qpsk quadriphased phase shift keying. Us20100165914a1 beam division multiple access system and. The polarization state is elliptical for all other values of. 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.
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. 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. Classification of multiple accesses and their protocols is shown in fig. Satellite communications architecture identify requirements. The paper begins by treating formatting, source coding, modulation, and potential tradeoffs for powerlimited systems and bandwidthlimited systems. They have a central core surrounded by a concentric cladding with slightly lower by. The duplex technology can be frequency or time division duplex synchronized or non synchronized. 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. Scribd is the worlds largest social reading and publishing site. Polarizationdivision multiplexing critical criteria.
Polarizationdivision multiplexed pdm transmission based on the nonlinear fourier transform nft is. Sdma uses spatial multiplexing and enables for higher data rate. Its technology divides a signal into different timeslots, and increases the data carrying capacity. The use of polarization division multiplexing pdm permits to multiply the. It isusually combined with other multiplexing techniques to better utilize the individual physical channels. Polarization tutorial rocky mountain instrument co. Wireless communication multiple access tutorialspoint. Elevation beamforming with full dimension mimo architectures. 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.
If the orientation of e q in fig 1 remains fixed as the wave moves forward, the light is planepolarized. 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. 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. 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 with polarization modulation for. It is used in microwave links such as satellite television downlinks to double the bandwidth by using two orthogonally polarized.
Maximum ratio transmission for spacepolarization division multiple access in dualpolarized mimo system. It facilitates many users to share the same frequency without interference. Multiple access protocols connectionless scheduling contention random access cdma. Polarization division multiple access pdma using dualpolarized antennas in high xpd could increase data rate by almost double via vertically and horizontally polarized channels. A structured overview of digital communicationsa tutorialu. Polarization is a property that is common to all types of vector waves. This paper focuses on the capacity of polarization division multiple access pdma channel to propose an optimal pdma power allocation scheme that refers. Scmbased passive optical networks pons enable multiple users to share. Interference can be near zero, even if mobile stations use the same allocated frequencies. This is in contrast to longitudinal waves, such as sound waves.
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. 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. Considering the applications of pf in radar and wireless communications for example 1723, the usage of polarization extends the available. 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. Figure 1b shows an example of two orthogonal sop represented in the poincare sphere. 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. Imt2000 is proposed to be the third generation standard and will use either a wideband cdma or tdma technology. 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. In the transmitter, there is a softwaredefined user code generator and a. Polarization division multiple access pdma is a method to simultaneously transmit two independent signals by using vertical and horizontal. Circular polarization and polarization losses by rastislav galuscak om6aa, pavel hazdra1. 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.
In this paper, we discuss a potential multiple access and modulation scheme. Any given polarization state corresponds to a unique point on the sphere. Fibers are typically made of silica with indexmodifying dopants such as geo 2. 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. This is the classical access method used in ethernet localarea networks lans. Pdf in this paper, we discuss a potential multiple access and modulation. Tech notes polarization tutorial light, as the electromagnetic wave, is characterized by its power, wavelength frequency, phase and polarization state. Dielectrics in electric fields polarization vector the polarization vector is a vector such that. Dec 11, 2014 it isusually combined with other multiplexing techniques to better utilize the individual physical channels. 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. In our analysis, a novel transceiver architecture for atmospheric ocdma fso systems based on polarization modulation with direct detection is. Polarizationdivision multiplexing based on the nonlinear. Scm based passive optical networks pons enable multiple users to share.
Figure 1 shows the basic architecture of the proposed ocdma system, which consists of a transmitter and receiver. In telecommunications, orthogonal frequencydivision multiplexing ofdm is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. When the waveplate is placed between parallel and perpendicular polarizers the transmissions are given by. The poincare sphere is used to describe the polarization and changes in polarization of a propagating electromagnetic wave. In classical physics, light is modeled as a sinusoidal electromagnetic wave in which an oscillating electric field and. Improving the nonlinear tolerance of polarizationdivision. Optical code division multiple access secure communications. The receiving radio constantly samples the incoming signals from both the antennas to determine the higher quality signal. There are many multiple access techniques evolved for sharing the common resources among multiple subscribers or users or clients. 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. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference mai and the system performance will be degraded. For light electromagnetic waves the vectors are the electric and magnetic fields, and the lights polarization direction is by. In this presentation suitable multiple access for future generations has been presented.
Stateof polarization encoding for optical code division multipleaccess networks. Polarization tutorial let e1 be initially polarized along x, and let the waveplate slow axis make an angle. Polarizationdivision multiple access pdma is a channel access method used in some. Wideband code division multiple access wcdma tutorial. Polarization division multiple access pdma is a channel access method used in some cellular networks. It provides a convenient way of representing polarized light, and of predicting how any given retarder will change the polarization form. Stateofpolarization encoding for optical codedivision.
The present invention is related to a beam division multiple access system and a method thereof. 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. However, the multiuser mimo technology then known as spatial division multiple access. The present paper describes the advantages of the combination of optical code division multiple access and polarization shift keying direct detection. 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. 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.
Us5515378a spatial division multiple access wireless. When cdm is used to allow multiple users to share a single communications channel, the technology is called code division multiple access cdma. Time division multiple access tdma is a digital cellular telephone communication technology. Maximum ratio transmission for space polarization division multiple access in dualpolarized mimo system. December 2009 learn how and when to remove this template message. A unique and widely used method of multiple access is carrier sense multiple access with collision detection csmacd. 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. 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. In addition, some other access schemes are usually used. Duplex and multiple access technology the calculation of the composite interfering signal depends on the duplex and multiple access technology used in the radios. Tutorial fiber basics optical fibers are circular dielectric waveguides that can transport optical energy and information. Polarization coordinates polarization table 1 shows the theoretical ratio of po wer transmitted between antennas of different polarization. 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.
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. One unique variation of sdma, polarization division multiple access pdma, separates signals by using different polarizations of the antennas. For each of these elements, we discuss how their design is impacted by mmwave radio propagation characteristics and present enabling mechanisms defined in. A study of dispersion compensation of polarization.
Polarization of light introduction light, viewed classically, is a transverse electromagnetic wave. The receiving radio constantly samples the incoming signals from both the antennas to. The polarization of light is one of the most remarkable phenomena in nature and has led to numerous discoveries and applications. Principle of polarization shift key optical code division multiple access. Code division multiplexing cdm is a networking technique in which multiple data signals are combined for simultaneous transmission over a common frequency band. Performance evaluation of optical code division multiple. Fundamentals of communications access technologies.
Osa polarization control of multiply scattered light. 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. Setting the frequency difference between two polarization orthogonal reference carriers as one subcarrier spacing, possible signal fading can be. Pressley maj james langley uk army dale white barry kruse shawn white ltc edward eidson thomas mims. When cdm is used to allow multiple users to share a single communications channel, the technology is. Namely, the underlying oscillation in this case oscillating electric and magnetic elds is along directions perpendicular to the direction of propagation. Polarization tutorial light, as the electromagnetic wave, is characterized by its power, wavelength frequency, phase and polarization state. Polarization division multiple access article about. Setting the frequency difference between two polarizationorthogonal reference carriers as one subcarrier spacing, possible signal fading can be. In cdma every user uses the full available spectrum instead of getting allotted by separate frequency. 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. Polarization division or dual polarization frequency reuse. 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.
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. Multiple access strategies fdma frequency division multiple access tdma time division multiple access cdma code division multiple access phase modulation plus pseudorandom noise. Ofdm has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, dsl internet. Polarization division multiple access pdma systems 4 6. Pdma is also multiple access technique which separates the signals using different polarisation type of teh antenna. Polarizationdivision multiple access pdma is a channel access method used in some cellular networks. Separate antennas are used in this type, each with different polarization and followed by separate receivers, allowing simultaneous regional access of satellites. This technology supports multiple connections on a single conventional channel where different users are identied by spatial signatures.
Wavelength division multiple access wdma is a related to fdma. 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. A coordinated transmission method based on beam division multiple access and an apparatus performing the same are disclosed. Frequency division multiple access tdma time division multiple access cdma code division multiple access. Top 124 sdma spatial division multiple access things you. Implementation of polarization matching technique for polarization.
Polarization division multiple access with polarization. A method and apparatus for increasing the capacity and quality of wireless communication between a plurality of remote users and a base station is disclosed. A description of the polarization of light to understand the polarization of light, we must first recognize that. Improving the nonlinear tolerance of polarizationdivision multiplexed coofdm in longhaul fiber transmission. Use past spacedivision multiple access goals and revise understanding of spacedivision multiple access architectures.
It comes from the greek word polos, for the axis of a spinning globe. Polarization division multiplexing of ofdm radiooverfiber. Field guide to polarization 2005 collett publications. Any polarization state of light at any spatial position behind the scattering medium can be attained with this technique. 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. 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. Osa pmd tolerant directdetection polarization division. Orthogonal frequencydivision multiplexing wikipedia. If the vector appears to rotate with time, then the wave is elliptically polarized. In this paper, we take a new angle of view at the application of polarization for wireless communications. Aug 25, 2011 in this paper, we take a new angle of view at the application of polarization for wireless communications. For light electromagnetic waves the vectors are the electric and magnetic. Army in transformation c4isrc2 architecture cpt corey s. Research open access polarization division multiple access.
Second generation standards include gsm global system for mobile and is6, using time division multiple access tdma, and is95 using code division multiple access cdma. In telecommunications, orthogonal frequency division 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. Communications via satellites have two unique charac. Canvass polarizationdivision multiplexing visions and reinforce and communicate particularly sensitive polarizationdivision multiplexing decisions. Pdf polarization division multiple access with polarization.
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