Receiver apparatus for receiving a multicarrier signal
First Claim
1. A receiver apparatus configured to receive a multicarrier signal comprising subcarriers, wherein multiple symbols are modulated onto the subcarriers, the receiver apparatus comprising:
- an estimation unit configured to;
estimate a subcarrier-dependent channel frequency response;
determine an intercarrier interference spreading on the basis of a cyclic shift in the symbols by determining a zeroth order time derivative of the channel frequency response for the subcarriers and at least a first order time derivative of the channel frequency response for the subcarriers according to a first or higher order approximation so as to estimate the channel frequency response; and
an equalizer unit configured to at least approximately canceling an intercarrier interference included in the multicarrier signal received on the basis of at least the channel frequency response estimated and the determined intercarrier interference spreading.
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Accused Products
Abstract
In time varying OFDM systems, the effect of a non-ideal time synchronization may lead to a poor performance in terms of decoded average bit error rate versus the signal-to-noise ratio. The receiver apparatus (3) of the transmission system (1) estimates a subcarrier-dependent channel frequency response and determines an intercarrier interference spreading on the basis of a cyclic shift in symbols carried by the subcarriers. Therewith, an intercarrier interference included in an OFDM signal can be canceled, even in case of a non-ideal time synchronization.
11 Citations
17 Claims
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1. A receiver apparatus configured to receive a multicarrier signal comprising subcarriers, wherein multiple symbols are modulated onto the subcarriers, the receiver apparatus comprising:
an estimation unit configured to; estimate a subcarrier-dependent channel frequency response; determine an intercarrier interference spreading on the basis of a cyclic shift in the symbols by determining a zeroth order time derivative of the channel frequency response for the subcarriers and at least a first order time derivative of the channel frequency response for the subcarriers according to a first or higher order approximation so as to estimate the channel frequency response; and an equalizer unit configured to at least approximately canceling an intercarrier interference included in the multicarrier signal received on the basis of at least the channel frequency response estimated and the determined intercarrier interference spreading. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A receiver apparatus configured to receive a multicarrier signal comprising subcarriers, wherein multiple symbols are modulated onto the subcarriers, the receiver apparatus comprising:
an estimation unit configured to; estimate a subcarrier-dependent channel frequency response; and determine an intercarrier interference spreading on the basis of a cyclic shift in the symbols; and an equalizer unit for at least approximately canceling an intercarrier interference included in the multicarrier signal received on the basis of at least the channel frequency response estimated and the determined intercarrier interference spreading, wherein the estimation unit is configured to determine the zeroth order time derivative of the channel frequency response for the subcarriers as a matrix for the zeroth order time derivative of the channel frequency response, the first order time derivative of the channel frequency response for the subcarriers as a matrix for the first order time derivative of the channel frequency response, the fixed intercarrier interference spreading as a matrix for the fixed intercarrier interference spreading, and the cyclic shift as a complex-valued function depending on a shift variable and the subcarriers, that the estimation unit is configured to determine a matrix for the intercarrier interference spreading on the basis of the cyclic shift function and the fixed intercarrier interference spreading matrix, the equalizer unit is configured to determine a vector of the signal output as a sum of a product of the matrix for the zeroth order time derivative of the channel frequency response and a vector of the symbols of the subcarriers, and a product of the matrix for the intercarrier interference spreading, the matrix for the first order time derivative of the channel frequency response and the vector of the symbols of the subcarriers.
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10. A receiving method for receiving a multicarrier signal comprising subcarriers, wherein multiple symbols are modulated onto the subcarriers, the method comprising:
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estimating a subcarrier-dependent channel frequency response; determining an intercarrier interference spreading on the basis of a cyclic shift in the symbols by determining a zeroth order time derivative of the channel frequency response for the subcarriers and at least a first order time derivative of the channel frequency response for the subcarriers according to a first or higher order approximation so as to estimate the channel frequency response; and approximately canceling an intercarrier interference included in the multicarrier signal received on the basis of at least the channel frequency response estimated and the determined intercarrier interference spreading. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification