Optical fiber based on wireless scheme for wideband multimedia access
First Claim
1. In a central base station of a communications network, wherein the central base station communicates over a channel with multiple portable units, the channel having a channel impulse response h(n) and the channel contributing linear and nonlinear distortion to a signal x(n) transmitted over the channel, an equalizer comprising:
- a polynomial filter for receiving signals from the portable units and for producing an output signal z(n) that is compensated for nonlinear channel distortion; and
a filter section following the polynomial filter for compensating for linear channel distortion.
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Accused Products
Abstract
A Fiber-wireless uplink consists of a wireless channel followed by a radio-over-fiber (ROF) link. Typically, nonlinear distortion of the ROF link is the major concern when the radio frequency is only a few GHz. This especially severe in the uplink, because of the multipath fading of the wireless channel. A Hammerstein type decision feedback equalizer is described for the fiber wireless uplink, that compensates for nonlinear distortion of the ROF link as well as linear dispersion of the wireless channel. Since the linear and nonlinear parts of the receiver are separated, tracking the fast changing wireless channel is virtually independent of compensating for the relatively static nonlinearity. Analytical results show that the receiver provides excellent compensation with notably less complexity.
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Citations
13 Claims
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1. In a central base station of a communications network, wherein the central base station communicates over a channel with multiple portable units, the channel having a channel impulse response h(n) and the channel contributing linear and nonlinear distortion to a signal x(n) transmitted over the channel, an equalizer comprising:
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a polynomial filter for receiving signals from the portable units and for producing an output signal z(n) that is compensated for nonlinear channel distortion; and
a filter section following the polynomial filter for compensating for linear channel distortion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification