Polarization-division multiple access (PDMA) is a

channel access method In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical ...

used in some

cellular network A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless network, wireless and the network is distributed over land areas called ''cells'', each served by at least one fixed-locatio ...

s and broadcast satellite services. Separate antennas are used in this type, each with different

polarization Polarization or polarisation may refer to: Mathematics *Polarization of an Abelian variety, in the mathematics of complex manifolds *Polarization of an algebraic form, a technique for expressing a homogeneous polynomial in a simpler fashion by ...

and followed by separate receivers, allowing simultaneous regional access of

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

s. Each corresponding

ground station A ground station, Earth station, or Earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves fr ...

antenna needs to be polarized in the same way as its counterpart in the satellite. This is generally accomplished by providing each participating ground station with an antenna that has dual polarization. The

frequency band Spectral bands are regions of a given spectrum, having a specific range of wavelengths or frequencies. Most often, it refers to electromagnetic bands, regions of the electromagnetic spectrum. More generally, spectral bands may also be means in ...

allocated to each antenna beam can be identical because the uplink signals are

orthogonal In mathematics, orthogonality (mathematics), orthogonality is the generalization of the geometric notion of ''perpendicularity''. Although many authors use the two terms ''perpendicular'' and ''orthogonal'' interchangeably, the term ''perpendic ...

in polarization. This technique allows

frequency reuse A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless network, wireless and the network is distributed over land areas called ''cells'', each served by at least one fixed-locatio ...

See also