OFDM receiver for dispersive environment
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsAndres Reial, Bengt Lindoff
Life of this patent
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Abstract
A received OFDM signal is processed to determine a plurality of reference delays, which may include the path delays of a multipath channel. The effective channel estimates corresponding to each reference delay are determined, as is the covariance of the ISI and noise components observed at each delay. Combining weights resulting in maximum post-combining SINR are determined for all subcarriers. A corresponding plurality of FFTs is applied to the incoming sample stream, one at each of the reference delays. The individual subcarriers from each FFT output are then combined using the combining weights. This produces a single FFT output with suppressed ISI, which is used in further processing.
Claims18
A method of processing a received Orthogonal Frequency Division Multiplexing (OFDM) signal in a wireless communication receiver, comprising:
- receiving the OFDM signal at one or more antennas;
- determining at least two reference delays per OFDM symbol per receiver antenna in the received signal;
- Fast Fourier Transform (FFT) processing the received signal at each determined reference delay to generate at least two sets of frequency domain samples;
- determining combining weights for the sets of frequency domain samples;
- combining the at least two sets of frequency domain samples using the combining weights;
- and
- detecting symbols from the combined frequency domain samples.
An Orthogonal Frequency Division Multiplexing (OFDM) receiver, comprising:
- one or more antennas operative to receive an OFDM signal;
- a timing control unit operative to generate a plurality of FFT processing reference delays;
- a Fast Fourier Transform (FFT) processor operative to FFT process the received signal at two or more reference delays, to generate two or more sets of frequency domain samples, in response to the timing control unit;
- and
- a symbol detector operative to generate combining weights, and to combine the sets of frequency domain samples based on the combining weights to detect OFDM symbols.
Dependencies are inferred from the claim text.