Telefonaktiebolaget Lm Ericsson (publ)

Nokia Siemens Networks Gmbh & Co Kg

Medielma S.r.l.

Umberto Spagnolini

Mauro Arigossi

Jonathan Gambini

Claudio Santacesaria

Monica Nicoli

Luigi Sampietro

Osvaldo Simeone

Carlo Bellorofonte

Michelangelo Canonico

A femtocell telecommunication system equipment comprising:

Equipment for femtocell telecommunications system

A femtocell telecommunication system equipment comprising: a base apparatus structured to provide a first information signal and control signals; an electrical conductor based transmission line connected to said base apparatus; a bidirectional conversion apparatus adapted to receive/transmit from/on the transmission line the first signal and the control signals; the bidirectional apparatus comprising: a processing module structured to process the first signal to generate a second information signal and vice-versa; the second signal being adapted to be transmitted/received by an antenna device connectable to the bidirectional apparatus.

A channel response matrix gathering all unknown elements for all K pilot subcarriers on links between transmitting and receiving antennas, is Least Squares (full-rank) estimated. The interference covariance matrix is estimated from the residual. The correlation of the interference covariance matrix is computed at each new symbol and compared with a threshold. If the interference is significantly changed, the interference covariance matrix is re-initialized, otherwise a running average of the interference covariance matrix is updated with the actual value. Both the updated/re-initialized interference covariance matrix and the autocorrelation matrix of the transmitted pilot sequences (stored in the receiver) are used for whitening the estimated channel matrix before submission to modal filtering for rank reduction. The original spatial and/or temporal correlations are reintroduced in the reduced-rank channel matrix by inverse whitening. After estimation in the discrete-time domain, DFT for conversion is applied for estimation in the whole frequency band.

Method to improve channel estimate in broadband SIMO/MIMO cellular radio networks during abrupt interference variations

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Lissone, Italy

Umberto Spagnolini