US 8,897,353 B2Granted

Block time domain channel estimation in OFDM system

AssigneeAcorn Technologies, Inc.

InventorsSteven C Thompson, Fernando Lopez de Victoria

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Abstract

An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Claims20

Dependent claims

An OFDM receiver that determines a time domain channel impulse response, the receiver comprising:

a filter that receives OFDM symbols, the filter comb filtering and puncturing OFDM symbols to provide punctured OFDM symbols having pilot information and having at least some data information removed;
punctured OFDM symbol storage to receive and store a number of punctured OFDM symbols;
a virtual pilot generator coupled to the punctured OFDM symbol storage to generate virtual pilot information for a plurality of OFDM symbols based on one or more of the punctured OFDM symbols, the virtual pilot information based at least in part on the pilot information;
a time domain channel estimator that processes a first punctured OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol;
and
a frequency equalizer that equalizes the first OFDM symbol in response to the channel impulse response for the first OFDM symbol.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/835,305Filed 15 Mar 2013
Published: US 2014/0269882 A118 Sep 2014
Granted: 25 Nov 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04L 27/2695
Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation: with…
H04L 25/0212
Channel estimation: of impulse response
H04L 25/0218
Of impulse response: with detection of nulls
H04L 25/022
Channel estimation: of frequency response