Alcatel

Dialog Semiconductor Gmbh

Alcatel Alsthom Compagnie Generale D'electricite

Michael Maurer

Michael Walker

Andreas Adler

Hans-Jürgen Matt

A method is described by which digital data can be sent between mobile phones concurrent with speech during a same phone call. The digital data can be from a digital camera that is integrated with the mobile, or cellular, phone. The discontinuous transmission system of the mobile phone system is modified to include a transmission handler that is used to control the packetizing of the digital data to be transmitted within the voids in the transmitted speech determined by a voice activated detector. A reception handler is added to the discontinuous transmission system to allow the extraction of the digital data from the transmitted mobile phone system signal.

Data and voice transmission within the same mobile phone call

A communication device such as a cellular or wireless telephone handset has a light display, such as handset cover light or display backlight, synchronized to audio signals from multiple audio sources such as a microphone or AM/FM receiver. The communication device further includes an audio to illumination conversion apparatus for modulating the light display in response to the audio signal. The audio to illumination conversion apparatus has a plurality of audio filter circuits for filtering the audio signal to restrict frequency content of the audio signal to a pass-band. Multiple integration circuits generate an energy content signal indicating an energy level within the pass-band and for the whole spectrum of the audio signal. An illumination modulator generates a modulation pattern for the light display in response to the energy content signals from a predefined light show.

Modulation of a background light or any illumination of a mobile phone

Method for the reduction of echo and/or noise signals in TK systems for the transmission of useful acoustic signals, in which, when a silence interval is present, the distorted useful signal is modified by a time-dependent control signal a(t) or by a control signal a(k) cycled in the rhythm of a scan rate f=1/T. The control signal a(k) is varied in such manner that, during the presence of speech signals in the useful signals, the amplitude of the control signal a(k) is set to a predetermined constant value cand, when a silence interval begins, the amplitude of the control signal a(k) is reduced continuously from one sample value to the next in accordance with the recurrence formula a(k+1)=a(k).&#x3b2; with &#x3b2;&#x3c;1. After the end of the silence interval, a(k) is again set equal to c.

Exponential echo and noise reduction in silence intervals

A method of canceling echoes in a telecommunications system wherein an exchange of information takes place between a local subscriber and a subscriber at the remote end of a transmission link and at least one subscriber is assigned an echo canceller, the parameters of which are set as a function of an echo delay time (i). The signs of the signal x(t) transmitted by a subscriber and the signal y(t) received by the subscriber can be determined at equidistant time intervals (T ) so that sign sequences arise which are stored and compared with one another, and in the event of a direct correspondence or a correspondence as a result of an inversion of the sign sequences of the received signal y(t) and of the transmitted signal x(t) the received signal y(t) is detected as an echo and the echo delay time (i) is calculated.

Method of cancelling echoes in a telecommunications system and an echo canceller for the execution of the method

Digital filters are used to simulate the transmission function of a real system by means of echo cancellers, where a high-speed digital signal processor with a large memory is needed to compute and update the filter coefficients. To reduce the cost of the echo canceller, an autocorrelation, i.e. the correlation of a block of a defined number of sampling values of the transmitted signal with received echoes derived from this transmitted signal, is used by the invention to determine the time periods at which an echo arrives, and at which an update of the filter coefficients then takes place. In this way the number of filter coefficients to be computed and the cost of their computation are significantly reduced, so that echo cancellers for telephone terminals can be produced in a cost-effective manner.

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Waiblingen, Germany

Michael Maurer