Abstract:
In this correspondence, blind channel estimators exploiting finite alphabet constraints are discussed for orthogonal frequency-division multiplexing (OFDM) systems. Cons...Show MoreMetadata
Abstract:
In this correspondence, blind channel estimators exploiting finite alphabet constraints are discussed for orthogonal frequency-division multiplexing (OFDM) systems. Considering the channel and data jointly, a joint maximum-likelihood (JML) algorithm is described, along with identifiability conditions in the noise-free case. This approach enables development of general identifiability conditions for the minimum-distance (MD) finite alphabet blind algorithm of Zhou and Giannakis. Both the JML and MD algorithms suffer from high numerical complexity, as they rely on exhaustive search methods to resolve a large number of ambiguities. We present a substantially more efficient blind algorithm, the reduced complexity minimum distance (RMD) algorithm, by exploiting properties of the assumed finite-length impulse response (FIR) channel. The RMD algorithm exploits constraints on the unwrapped phase of FIR systems and results in significant reductions in numerical complexity over existing methods. In many cases, the RMD approach is able to completely eliminate the exhaustive search of the JML and MD approaches, while providing channel estimates of the same quality.
Published in: IEEE Transactions on Information Theory ( Volume: 53, Issue: 3, March 2007)
Citations are not available for this document.
Cites in Patents (3)Patent Links Provided by 1790 Analytics
1.
DHAYNI, Achraf, "A NEW INTERPOLATION ALGORITHM FOR PILOT-BASED CHANNEL ESTIMATION IN OFDM SYSTEMS"
Inventors:
DHAYNI, Achraf
Abstract:
An OFDM receiver (1) such as a WiFi receiver receives data via a plurality of data subcarriers and a plurality of pilot subcarriers. The data and pilot signals are processed through a conventional demultiplexer (2) and DFT(3) before delivering each pilot signal to a transfer function estimation module (4). The transfer function estimation module (4) includes a Cartesian to polar coordinate conversion module (5) to convert each pilot signal to polar form and facilitate separate calculation of amplitude and phase transfer functions. An amplitude phase transfer function and phase transfer function is then calculated for each data subcarrier and used to form a complex transfer function for each subcarrier. The complex transfer function is then applied to each respective subcarrier via an equaliser to equalise each data subcarrier and correct for data signal corruption caused by attenuation noise or other factors.
Assignee:
ST-ERICSSON SA
Filing Date:
10 September 2013
Grant Date:
07 October 2015
Patent Classes:
Current International Class:
H04L0250200000, H04L0250300000, H04L0272600000
2.
Dhayni, Achraf, "A new interpolation algorithm for pilot-based channel estimation in OFDM systems"
Inventors:
Dhayni, Achraf
Abstract:
An OFDM receiver (1) such as a WiFi receiver receives data via a plurality of data subcarriers and a plurality of pilot subcarriers. The data and pilot signals are processed through a conventional demultiplexer (2) and DFT(3) before delivering each pilot signal to a transfer function estimation module (4). The transfer function estimation module (4) includes a Cartesian to polar coordinate conversion module (5) to convert each pilot signal to polar form and facilitate separate calculation of amplitude and phase transfer functions. An amplitude phase transfer function and phase transfer function is then calculated for each data subcarrier and used to form a complex transfer function for each subcarrier. The complex transfer function is then applied to each respective subcarrier via an equaliser to equalise each data subcarrier and correct for data signal corruption caused by attenuation noise or other factors.
Assignee:
ST-ERICSSON SA
Filing Date:
02 September 2013
Grant Date:
15 October 2014
Patent Classes:
Current International Class:
H04L0250200000, H04L0250300000, H04L0272600000
3.
DHAYNI, Achraf, "A NEW INTERPOLATION ALGORITHM FOR PILOT-BASED CHANNEL ESTIMATION IN OFDM SYSTEMS"
Inventors:
DHAYNI, Achraf
Abstract:
An OFDM receiver (1) such as a WiFi receiver receives data via a plurality of data subcarriers and a plurality of pilot subcarriers. The data and pilot signals are processed through a conventional demultiplexer (2) and DFT(3) before delivering each pilot signal to a transfer function estimation module (4). The transfer function estimation module (4) includes a Cartesian to polar coordinate conversion module (5) to convert each pilot signal to polar form and facilitate separate calculation of amplitude and phase transfer functions. An amplitude phase transfer function and phase transfer function is then calculated for each data subcarrier and used to form a complex transfer function for each subcarrier. The complex transfer function is then applied to each respective subcarrier via an equaliser to equalise each data subcarrier and correct for data signal corruption caused by attenuation noise or other factors.
Assignee:
ST-ERICSSON SA
Filing Date:
10 September 2013
Grant Date:
20 March 2014
Patent Classes:
Current International Class:
H04L0250200000, H04L0250300000, H04L0272600000
