A method and apparatus for cooperation in wireless communications. Cooperation is considered among a number of network elements, including at least one wireless transmit-receive unit, at least one relay station, and at least one base station.

Method and apparatus for cooperative wireless communications

Methods and apparatus for supporting and using multiple communications channels corresponding to different transmit technologies and/or access technologies in parallel within a cell of a wireless communications system are described. Mobile nodes support multiple technologies and can switch between the technology being used at a particular point in time, e.g., from a first channel corresponding to a first technology to a second channel corresponding to a different technology which provides better transmission characteristics, e.g., a better perceived channel quality. Mobiles maintain at least two sets of channel quality information at any one point in time. Mobiles select the better channel and communicate the channel selection to the base station or communicate channel quality information for multiple channels to the base station and allow the base station to select the channel corresponding to the technology providing the better conditions for the mobile. Different mobiles in the same cell may support different technologies.

Methods and apparatus of enhancing performance in wireless communication systems

Pilot signal transmission sequences and methods are described for use in a multi-sector cell. Pilots in different sectors are transmitted at different known power levels. In adjacent sectors a pilot is transmitted while no pilot is transmitted in the adjoining sector. This represents transmission of a NULL pilot signal. A cell NULL is also supported in which NULL pilots are transmitted in each sector of a cell at the same time. Multiple pilot signal measurements are made. At least two channel quality indicator values are generated from measurements corresponding to at least two pilot signals of different power levels. The two values are transmitted back to the base station which uses both values to determine the transmit power required to achieve a desired SNR at the wireless terminal. The wireless terminal also reports information indicating its location to a sector boundary.

Pilot signals for use in multi-sector cells

A method transmits data. The method includes transmitting a series of data unit, receiving a retransmission request indicating a plurality of corrupt data units in the transmitted data units which were not received correctly, and retransmitting the corrupted data units.

Data Transmission And Retransmission

A beam-forming system comprises a cooperative array of wireless terminals coupled to at least one wireless wide area network (WWAN) and communicatively coupled to a wireless local area network (WLAN) configured to provide information exchanges between the wireless terminals. A cooperative beam-forming system employing the WLAN provides antenna-array processing benefits (such as frequency reuse, interference rejection, array-processing gain, antenna-switching diversity) to the individual wireless terminals. A network access operator facilitates network control functionality between the WWAN and the cooperative array of wireless terminals.

Cooperative beam-forming in wireless networks

The WCDMA uplink has recently been enhanced with hybrid ARQ, scheduling, and shorter TTI to provide improved performance for packet data services in terms of reduced delays, improved availability of high data rates, and increased capacity. This paper gives an overview of the design targets, the basic principles, and how they are integrated into WCDMA.

WCDMA enhanced uplink - principles and basic operation

A method and apparatus for providing a link quality report in a wireless communication system supporting link adaptation. An input signal carrying data blocks in one or several transmission intervals of a reporting interval is received by a receiver (30) of the apparatus. A quality measurement unit (31) provides a link quality measure of the current reporting interval. A correction unit (32) corrects the link quality measure by determining a SIR loss of the link, which is induced by unmatched transmission parameter settings of a physical layer. Then, a link quality report for the current reporting interval is based on the corrected link quality measure and transmitted by the transmitter (34) to the transmitting unit, which will adapt the setting of physical layer parameters accordingly.

Method and apparatus for link adaptation

Methods and systems using short link radios (SLRs) with mobile terminals are disclosed. A mobile terminal having a SLR connects to other mobile terminals having SLRs over a SLR link to increase the troughput, the QoS, or both of the system. The mobile terminals establish a SLR link between a first mobile terminal and a second mobile terminal. Both mobile terminals receive data transmitted from a base station intended for the first mobile terminal. The second mobile terminal then retransmits the data received by the second mobile terminal to the first mobile terminal via the SLR link.

Systems using mobile terminals having short link radios

A sub-optimal method is disclosed for calculating the reliability values (soft values) for the bits of a multilevel signal. The log-likelihood values are approximated using only the dominant terms, so called max-log approximation, that is for each bit position only the two closest signal symbols of opposite bit value (S 8 ,S 6 ) are considered in the sum. The used modulation scheme is 16-QAM together with Gray-labelling. Two versions of approximation are proposed: one version consists of using the two distances between the received value and the two closest symbols of opposite bit value (δ 1 , δ 2 ). In order to simplify and speed up the calculation, the second version consists of using the distance between the two closest symbols (δ 3 ) to approximate the distance between the second closest symbol and the received value. Furthermore, precalculated results are stored in look-up tables to speed up the calculation. Possible applications are especially bit interleaved coded modulation (BICM) together with soft-input decoding. It is also of interest for TCM and BCM schemes.

Soft value calculation for multilevel signals

In accordance with exemplary embodiments of the invention, throughput and capacity in a TDMA system are increased using several different channels all operating simultaneously on the same carrier frequency. In a first embodiment, a base station in a cell in the system simultaneously transmits a different information sequence from each antenna of a transmitter, on the same carrier frequency. Mobile stations in the cell each receive the signals from the base station antennas as a composite signal, and then use known synchronization information to extract a desired information sequence from the composite signal. In a second embodiment, the different information sequences are all intended for the same mobile station, which uses the synchronization information to extract each sequence from the composite signal. In a third embodiment of the invention, the base station simultaneously transmits identical information sequences to a mobile station via different antennas. The mobile station uses the resulting space diversity effect to obtain diversity gain that enables an increase in the number of channels per area-unit, and thus an increase in traffic and spectrum efficiency. The system can also dynamically employ these to effectively respond to changing demands for communications services within the system.

Method and apparatus for increasing throughput and/or capacity in a TDMA system

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