Abstract: Embodiments may relate to an audio system for playback of an audio signal, for example in a motor vehicle. The audio system may include a virtualization speaker located in a position that would be in front of a listener of the audio system. The audio system may further include a user speaker located in a position that would be behind a listener of the audio system. In some embodiments the virtualization speaker may be configured to play a virtualization audio signal while the user speakers are configured to play an audio signal which at least partially overlaps the virtualization audio signal. In some embodiments the virtualization audio signal may be at a different volume or a different frequency range than the audio signal. Other embodiments may be described or claimed.

Abstract: A cascaded optical amplifier including a first optical amplifier and a second optical amplifier in cascaded arrangement is provided. Each of the first optical amplifier and the second optical amplifier has a respective input for receiving an optical signal, an output for outputting an amplified optical signal, and a control input for controlling the gain of the optical amplifier. The cascaded optical amplifier includes a sensor for sensing upstream of the input of the second optical amplier a signal relating to operation of the cascaded optical amplifier. In addition, the cascaded optical amplifier includes a controller for providing control signals to the respective control inputs of the first amplifier and the second amplifier, the controller providing the control signal to the second optical amplifier as a function of the sensed signal.

Abstract: A cascaded optical amplifier including a first optical amplifier and a second optical amplifier in cascaded arrangement is provided. Each of the first optical amplifier and the second optical amplifier has a respective input for receiving an optical signal, an output for outputting an amplified optical signal, and a control input for controlling the gain of the optical amplifier. The cascaded optical amplifier includes a sensor for sensing upstream of the input of the second optical amplier a signal relating to operation of the cascaded optical amplifier. In addition, the cascaded optical amplifier includes a controller for providing control signals to the respective control inputs of the first amplifier and the second amplifier, the controller providing the control signal to the second optical amplifier as a function of the sensed signal.

Abstract: A method and apparatus for compensating, in the electrical domain, for chromatic dispersion of an optical signal is disclosed. A received optical signal is converted to an electrical signal. The spectrum of the electrical signal is amplified by a factor derived from its frequency; and the phase of regions of said spectrum is selectively inverted to thereby allow recovery of the transmitted data. The optical signal may have a non-infinite extinction ratio to improve recovery of the transmitted signal. The square root of the electrical signal may be taken to improve recovery of the transmitted signal.

Abstract: A method and apparatus for compensating, in the electrical domain, for chromatic dispersion of an optical signal is disclosed. A received optical signal is converted to an electrical signal. The spectrum of the electrical signal is amplified by a factor derived from its frequency; and the phase of regions of said spectrum is selectively inverted to thereby allow recovery of the transmitted data.

Abstract: An array of stimulators associated with a personal communications device for providing the user with tactile messaging respecting call processing or call network status. The array is positioned on the device so as to be in contact with the user while the terminal is carried or worn, on a wrist, for example. The stimulators of the array, are activated independently so as to provide the user with an encoded message of call processes such as alerting, dial tone, busy signal, etc. Preferably each status is associated with one of a set of unique patterns of operation of the stimulators recognizable by the user as tactile image or pattern of operation, rather than necessitating tactile sensation of individual sequences of each stimulator. Advantageously audio and haptic signalling is synchronised to provide a tactile warning to alert user to impending audio signal, and thereby allow a lower level, i.e. quieter, audio signal to be used, because the user is primed by the tactile signal to expect the audio signalling.

Abstract: A transmitter includes a pair of electrodes separated in space, and transmit circuitry for varying the voltage difference applied across the electrodes in order to vary the spatial gradient of the electric potential field generated by the transmitter in accordance with the data to be transmitted. The receiver includes a pair of electrodes separated in space and receive circuitry which detects these variations in the quasi-electrostatic potential field in order to receive the transmitted data. Thus the receive electronics unit includes a detector connected to said electrodes for producing a signal which varies as the spatial gradient of the electric potential field across the receive electrodes varies but which does not depend on changes in potential within any given electrode.