Sony Deutschland Gmbh

Sony International (europe) Gmbh

Besma Kraiem

Janos Enderlein

Veselin Brankovic

Jens Wildhagen

Markus Zumkeller

A calibration procedure of wireless networks to create a topology map mainly consists of two phases: a measurement phase during which each wireless device, i. e. all mobile terminals end the central controller transmits a calibration signal in broadcast mode (S, S, S) and each other wireless device measures the received signal quality and the reporting phase during which each mobile terminal reports the measured results to the central controller of the network (S, S). Both of these phases are preferably initiated by the central controller the measurement phase with the broadcast of a measurement control signal to all mobile terminals (S) and the reporting phase with the broadcast of a reporting control signal to all mobile terminals (S). Based on all measurement results the central controller creates a topology map of the network once all reports have been received. This topology map is updated in two cases, namely when a new device joins the network with a high priority calibration and when a timer expires with a low priority calibration. i. e. only when there are enough free resources.

Calibration procedure for wireless networks with direct mode traffic

A calibration procedure of wireless networks to create a topology map mainly consists of two phases: a measurement phase during which each wireless device, i.e. all mobile terminals end the central controller, transmits a calibration signal in broadcast mode (S, S, S) and each other wireless device measures the received signal quality and the reporting phase during which each mobile terminal reports the measured results to the central controller of the network (S, S). Both of these phases are preferably initiated by the central controller, the measurement phase with the broadcast of a measurement control signal to all mobile terminals (S) and the reporting phase with the broadcast of a reporting control signal to all mobile terminals (S). Based on all measurement results the central controller creates a topology map of the network once all reports have been received. This topology map is updated in two cases, namely when a new device joins the network with a high priority calibration and when a timer expires with a low priority calibration, i.e. only when there are enough free resources.

An OFDM telecommunication device, i.e. a receiver, transmitter or transceiver for OFDM&#x2014;(Orthogonal Frequency-Division Multiplex) signals that generally employs the Inverse Fourier Transformation (IFT) technique to encode and transmit time-division multiplex signals and the Fourier Transformation (FT) technique to decode the received signals into time-division multiplex signals comprises a transformation unit () that incorporates at least an analog multiplication step and at least an analog convolution step of a multiplication convolution multiplication algorithm or a convolution multiplication convolution signal to perform a fourier transformation for demodulation and/or an inverse fourier transformation for modulation into the analog stage of said OFDM telecommunication device.

Telecommunication device with analog fourier transformation unit

The invention proposes the separate processing of the phase and amplitude of multi-amplitude digital modulation techniques, such as a QAM. The phases are differentially modulated and the amplitudes coherently processed. Also proposed is a method to correct the amplitude distortion of the symbols on each subcarrier, either from the QAM signal itself or from any PSK signal, if available. The invention shows that differential modulation/demodulation of multi-amplitude signals with no equidistant phases such as QAM is possible. Complex equalizer means to perform a channel estimation is no more needed as for coherent systems. Further, no pilot sucarriers are needed, thus the bandwidth efficiency is much higher. Furthermore, the frequency snychronization of differential demodulated signals is less complex. An implementation proposal of the new modulation/demodulation technique is described.

Quasi-differential modulation/demodulation method for multi-amplitude digital modulated signals and OFDM system

A transmit power control applicable for direct mode in a central controller based wireless network is described whereby direct mode indicates a direct communication of two network terminals () without routing the traffic through the central controller (). According to the present invention the transmit power control is performed by means of exchanging messages (S, S, S) between the peer network devices () in which recommendations for power control are carried. After grant of resources (S) by the central controller () for the peer mobile terminals () to exchange such messages which neccessarily contain a recommendation to the peer neetwork device to increase/decrease its transmit power level by a certain value, a first message (S) is send from one network device () to the other network device () which receives this message and measures its signal strength to determine the needed adjustment to set the transmit power level of the first device so that a desired received power level of the second device is achieved. This adjustment value is then transmitted in a second step (S) as recommendation value whereafter the first device can similary recommend an adjustment of the transmit power level of the second device on basis of the message received in the second step (S) in a third step (S).

Transmit power control for network devices in a wireless network

Performing an antenna diversity set-up according to the present invention a first mobile terminal ( ) transmits a pre-defined antenna calibration signal to a second mobile terminal ( ) using its omni-directional antenna ( ). During the period of the transmitted signal the best receiving antenna (x) is identified at the second mobile terminal ( ) by switching all its directional antennas ( to ) and its omni-directional antenna ( ) into its receiving path and measuring the received signal quality, e.g. the received signal strength. The directional antenna (x) of the second network device ( ) which is identified as best receiving antenna is then used for transmission and reception of data transfer with the first network device ( ). Using this antenna, the second network device ( ) transmits its pre-defined calibration signal to the first network device ( ) which repeats a similar switching and measuring procedure with its directional antennas ( to ) and its omni-directional antenna ( ) to identify its best receiving antenna (y). These two antennas (x, y) identified at the second network device ( ) and the first network device ( ) are then used for direct data transfer in-between these both devices. This inventive method is preferably used in direct mode within an IEEE 1394 based HIPERLAN type 2 wireless network.

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Fellbach, Germany

Besma Kraiem