Commonwealth Scientific and Industrial Research Organisation

Other

Hajime Suzuki

Joseph Abraham Pathikulangara

David Eric Humphrey

Iain Bruce Collings

Douglas Brian Hayman

Zhuo Chen

Chang Kyung Sung

Rodney Kendall

Disclosed is a method, receiver, multi-receiver device, system and computer readable medium for configuring a receiver to perform multi-transmitter channel estimation for a time-varying channel. In one aspect, the method includes: wirelessly receiving at least two frames, each frame including a block of training symbols received at different points in time for a time-varying channel; estimating, for each block at a block location, a first channel coefficient of the time-varying channel, wherein the block location is the same for each block; and interpolating or extrapolating a plurality of second channel coefficients for the respective training symbols of each block based on the respective first channel coefficient.

Multi-transmitter channel estimation for a time varying channel

The present invention discloses various improvements to multi-user multiple-input multiple-output orthogonal frequency division multiplexing (MU-MIMO-OFDM) wireless communication systems. In one aspect there is disclosed an efficient and accurate channel estimation method and system using locally consecutive pilot sub-carriers. In another aspect there is disclosed an efficient channel feedback method and system by applying a discrete cosine transform to channel coefficients. In another aspect there is disclosed an efficient method and system to calculate a part of the channel inverse by interpolation. These aspects can be used in combination to improve the MU-MIMO-OFDM system.

Multi-user MIMO-OFDM system

Disclosed is a user terminal for wireless communication with a remote access point. The user terminal may include a mapping module adapted to map one or more input data bits to an uplink symbol, a delay module adapted to apply a delay to the uplink symbol, a transmit module adapted to modulate the delayed symbol into a frequency channel, and an antenna being adapted to transmit the modulated symbol to the access point. The delay can be chosen such that the transmitted symbol arrives at the access point simultaneously with a further symbol modulated into the frequency channel and transmitted by a further user terminal.

Fixed multiple access wireless communication

Disclosed is a user terminal for wireless communication with a remote access point, the user terminal comprising: a mapping module adapted to map one or more input data bits to an uplink symbol; a delay module adapted to apply a delay to the uplink symbol; a transmit module adapted to modulate the delayed symbol into a frequency channel; and a directional antenna oriented along a dominant path to the access point, the antenna being adapted to transmit the modulated symbol to the access point, wherein the delay is chosen such that the transmitted symbol arrives at the access point simultaneously with a further symbol modulated into the frequency channel and transmitted by a further user terminal.

An OFDM wireless communication system with an access point and a plurality of remote user terminals estimates an uplink channel. The access point receives training symbols transmitted by the user terminals. Each training symbol includes pilot symbols associated with phase offset estimation OFDM sub-carriers. The phase offset estimation sub-carriers include subsets of sub-carriers associated with each respective user terminals. Each subset is used exclusively by the associated user terminal during channel estimation. The channel estimation sub-carriers are used by all user terminals. For each terminal the access point estimates symbol-specific phase offsets specific to the user terminal using the received pilot symbols associated with the user specific subset of the phase offset estimation sub-carriers. The access point also estimates the uplink channel using the user-terminal-symbol-specific phase offset estimates and the received symbols.

Channel estimation in a multi-user MIMO-OFDM system in the presence of user terminal symbol-specific phase offsets

A user terminal for wireless communication with a remote access point can include a mapping module, a delay module, a transmit module, and a directional antenna. The mapping module can be used to map one or more input data bits to an uplink symbol. The delay module can be used to apply a delay to the uplink symbol. The transmit module can be used to modulate the delayed symbol into a frequency channel. The directional antenna can be oriented along a dominant path to the access point, and the antenna is used to transmit the modulated symbol to the access point. The delay is chosen such that the transmitted symbol arrives at the access point simultaneously with a another symbol that is modulated into the frequency channel and transmitted by another user terminal.

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Epping, Australia

Hajime Suzuki