Telefonaktiebolaget Lm Ericsson (publ)

Optis Wireless Technology, LLC

Johan Nyström

Erik Bengt Dahlman

Svante Signell

Pål Frenger

Stefan Parkvall

Farooq Khan

Pàl Frenger

David Astely

Yngve Selén

Lei Wan

Niklas Johansson

Anders Furuskär

Imadur Rahman

Henrik Asplund

Johan Sköld

Per Skillermark

Johan Axnäs

Tobias Tynderfeldt

Kai-Erik Sunell

Patrik Nils Lundqvist

Göran N Klang

Magnus K Almgren

Mats Cedervall

Muhammad Imadur Rahman

Pál Frenger

Göran Klang

Stefan JÄVERBRING

Patrik Lindqvist

Alex Jamal

A set of different pilot structures are designed for use in different environments and/or different user behaviours that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D) In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

Method and apparatus for allocating a pilot signal adapted to the channel characteristics

A set of different pilot structures are designed for use in different environments and/or different user behaviours that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D). In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

A set of different pilot structures are designed for use in different environments and/or different user behaviors that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D) In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

The technology disclosed provides the ability for a subframe to be configured as a 'flexible' subframe. As a result, at least three different types of subframes in a TDD system may be configured: a downlink ('DL') subframe, an uplink (&#x201c;UL&#x201d;) subframe, and a &#x201c;flexible&#x201d; subframe. While the DL and UL subframes are preconfigured for each frame instance, the flexible subframes are dynamically allocated to be an uplink subframe in one instance of a frame and a downlink subframe in another instance of the frame.

Flexible subframes

In a method of enabling synchronization for a channel in an OFDM based telecommunication system initially providing a symbol for transmission and selecting at least two carrier frequencies, subsequently determining a respective weighting parameter for the selected frequencies and finally transmitting the symbol on all selected frequencies based on the weighting parameters.

Synchronization in OFDM using polynomial cancellation coding

The object of the present invention is to provide a mechanism for a more efficient carrier search. The object is achieved by a method for sending a signal in a first node. The first node communicates with a second node via radio communication, which radio communication is performed by multi carrier transmission. The first node uses a carrier, being associated with a frequency range. The method comprises the step of transmitting an end-marker signal within or close to the frequency range. The end-marker signal is intended to be received and used by the second node for identifying the frequency range of the used carrier.

Method and arrangement in a communications system

Radio resources are allocated to communication between a mobile station and a base station. The available set of radio resources may comprise radio resources primarily assigned to a neighboring cell if the 5 mobile station experience an instantaneous low level of co-channel interference from such neighboring cells. The existence of interference is preferably deduced from signal quality measurements of pilot signals. The allocation may concern uplink and/or downlink communication. Devices for performing the measurements are located in the mobile station, while devices for performing the evaluation, selection and actual allocation can be placed in different parts of the communications system&#x2014;in the mobile station, in a base station or in a core network node, or as a distributed means.

Dynamic allocation of radio resources

A method for use in a cellular, FFT based multi-carrier communications system comprising N subcarriers, for allocating a set P of sub-carriers to be reserved for potential use as carriers of specific information. A number M indicating the number of sub-carriers to be allocated to a set P of sub-carriers, such that L=N/M is an integer. At least two subcarriers of the set P={(n+m*L) mod N : 0&#x2266;m&#x3c;M} for the specific information, nbeing the offset of the lowest numbered subcarrier in P, the elements of P being indices, each referring to the number of a sub-carrier to be allocated. An apparatus for carrying out the method is also disclosed. The sub-channels are maximally spread in frequency, which gives maximum diversity and also enables the use of low-complexity terminals.

Method and apparatus in a cellular telecommunications system

In a system applying orthogonal frequency division multiplexing, OFDM, a number of carriers are reserved for communication between unsynchronized nodes (N, N). At least one such reserved carrier is assigned to each base station. A sinusoidal signal is transmitted on this reserved carrier during a time period at least equal to two consecutive OFDM symbols. The unsynchronized receiver detects the sinusoidal signal during one of two consecutive OFDM symbol time periods. The existence, the frequency and the signal power of the signal give information about the existence and identity of the transmitter. Also, estimates of relative velocities and distances can be deduced. In preferred embodiments, the sinusoidal signal can also be used to transmit further information by using signal modulation or coding that is independent of the absolute signal phase.

Wireless multicarrier system with subcarriers reserved for communication between unsynchronized nodes

Growing community of inventors

Stockholm, Sweden

Johan Nyström