Methods and apparatus for adaptively transmitting data in a wireless communication network are disclosed, in which channel conditions between a mobile terminal and two or more base stations in an active set are evaluated and used to select a transmission mode from a set of available downlink transmission modes including a non-interference-coordinated point-to-point transmission mode as well as at least one of a multi-cell single-frequency-network transmission mode and an interference-coordinated point-to-point transmission mode. Using the dynamic transmission mode selection described herein, a higher cell-edge throughput in HSDPA systems may be achieved.

Methods and apparatus for improving cell-edge data throughput in a wireless communications system

Embodiments provide an apparatus, a method and a computer program for controlling transmission points in a mobile communication system. The apparatus 10 for controlling transmission points 20, 22 in a mobile communication system comprises means for dynamically allocating 12 a cluster of transmission points for joint communication with the mobile transceiver 100 to a set of processing resources 30 to commonly process the radio signals communicated with the mobile transceiver 100. The cluster of transmission points corresponding to a set of one or more transmission points 20, 22.

Apparatus, Method and Computer Program for Controlling Transmission Points in a Mobile Communication System

We evaluate the system-level performance and potential capacity gain of MBSFN (Multicast/Broadcast Single Frequency Network) operation in wideband CDMA (WCDMA) and compare it to conventional multimedia broadcast/multicast service (MBMS) provision with macro-diversity combining. MBSFN operation has recently been specified in the 3rd Generation Partnership Project (3GPP) as an enhancement to MBMS. It aims to mitigate the cell-edge problem of multicast/broadcast applications, which are typically dimensioned for a predefined coverage. In WCDMA as considered here, MBSFN operation refers to the use of a single common scrambling code and the same set of spreading codes to simultaneously broadcast bit identical MBMS data in a number of cells that form an MBMS cluster. Since intercell interference is drastically reduced by this concept, it has the potential of considerably increasing the spectral efficiency of MBMS. Nevertheless, coarse synchronization of the transmitting base stations is expected to degrade the performance of MBSFN. We study the system-level performance of MBSFN for WCDMA with imperfect synchronization of the base stations considering different equalization strategies.

On the Impact of Coarse Synchronization on the Performance of Broadcast/Multicast Single Frequency Network Operation in WCDMA

Each of two or more base stations notifies a communication controller of information on a first frequency band that the base station uses for radio communication. Based on the information on the first frequency bands acquired from the two or more base stations, the communication controller selects a second frequency band to be used by the two or more base stations to transmit the data with common content, and notifies the two or more base stations of information on the selected second frequency band. The two or more base stations transmit the data with common content based on the information on the second frequency band acquired from the communication controller.

Radio communication system, communication controller, and base station

Methods of processing signals, representing the same data, each of which is received over a corresponding one of a plurality of communication channels (3a-c) of a communication system, such as SCCPCHs in a WCDMA communication system, are disclosed. The methods utilize bit-error rates (120) of the signals estimated based on a received control sequence (115), such as a TFCI, or SIR differences between signals to determine which signals to softcombine (150), thereby facilitating to account for relatively rapid changes in the radio environment when determining which signals to softcombine. A corresponding computer program product, computer readable medium, signal processing unit, radio receiver circuit, and electronic apparatus are also disclosed.

Method and processing unit for processing signals with macro diversity

Multimedia broadcast/multicast services (MBMS) have been introduced for WCDMA in release 6. At a given coverage, the efficiency of conventional MBMS is limited by low SNR users as, e.g., users located close to a cell edge, which are typically suffering from bad channel and inter-cell interference conditions. As a means to mitigate the situations of such users, multicast/broadcast single frequency network (MBSFN) operation has recently been specified in the Third Generation Partnership Project (3GPP) as an enhancement of MBMS. In WCDMA downlinks as considered here, MBSFN operation refers to the coherent use of a single common scrambling code and the same spreading codes to simultaneously broadcast identical MBMS channels in a number of cells that form an MBMS cluster. Through this, the users receive the signals from the cluster of MBSFN cells as one single signal over a joint radio channel, which exchanges inter-cell interference by constructive multi-path signals. This can be exploited by advanced receivers to yield impressive receiver output SNR gains as compared to conventional MBMS. This paper presents an experimental evaluation of the spectral efficiencies achievable in MBSFN and conventional MBMS. The results help to assess whether it is expedient to enhance WCDMA by MBSFN.

Christoph A. Jotten

Papers

Performance Evaluation of Multicast/Broadcast Single Frequency Network Operation for WCDMA