Lakeside Labs Gmbh

Ntt Docomo, Inc.

Christian Bettstetter

Helmut Adam

Wilfried Elmenreich

Katsutoshi Kusume

Gerhard Bauch

Christian Hartmann

Robert Vilzmann

In a relay scheme, a wireless source apparatus, a wireless destination apparatus and a wireless relay apparatus cooperate for handling transmission failures by space/time diverse channels. In the case of the successful direct transmission, reduced or no additional overhead for the relay selection is incurred. Thus, for a good SNR between source and destination, the inventive protocol has similar performance as a standard approach. In the case of a transmission failure e.g., due to small scale fading, a transmission via a different communication path implementing spatial diversity via a selected relay is supported. The device is to only activate the overhearing of signals in case of weak signal quality between sender and receiver. This selection of relay devices is done by demand only. A specific protocol for the reservation of the wireless medium for the entire cooperative communication has been specified.

Apparatus and method for cooperative relaying in wireless systems using an extended channel reservation

In a relay scheme, a wireless source apparatus, a wireless destination apparatus and a wireless relay apparatus cooperate for handling transmission failures by space/time diverse channels. In the case of the successful direct transmission, reduced or no additional overhead for the relay selection is incurred. Thus, for a good SNR between source and destination, the inventive protocol has similar performance as a standard approach. In the case of a transmission failure e.g., due to small scale fading, a transmission via different communication paths implementing spatial diversity via a selected relay is supported. The device is to only activate the overhearing of signals in case of weak signal quality between sender and receiver. This selection of relay devices is done of demand only. A specific protocol for the reservation of the wireless medium for the entire cooperative communication has been specified.

Cooperative relay scheme having backward compatibility

A receiver includes a receiving unit for scanning a dedicated signaling channel for the presence of an announcement signal. The announcement signal indicates a transmitter willing to access a transmission medium. The receiving unit is further operative to receive a data signal from a further transmitter on a dedicated traffic channel. Furthermore, the receiver includes an interference estimator for estimating, whether an interference caused by a new transmitter is allowable or not. A processor is provided for applying an interference counter-measure, when the interference is not allowable. A transmitter can, without any limitation, transmit the announcement signal. The transmitter will start transmitting, when it receives a ready-to-receive signal from the addressed receiver and when it does not receive an objection tone from another receiver in the network.

Receiver and transmitter for a network having a non-centralized medium access control

Growing community of inventors

Klagenfurt, Austria

Christian Bettstetter