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System Technology. System Block Diagram Infra-Red Radiation Signal Processing Audio Channel Quality Modes Carriers and Channels Audio Encoding and Quality Transmission Protocol. I&O Manual. Transmission Protocol. Integrus Receiver. DCN Next Generation. DCN system. IntegrusRadiator.
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System Technology • System Block Diagram • Infra-Red Radiation • Signal Processing • Audio Channel Quality Modes • Carriers and Channels • Audio Encoding and Quality • Transmission Protocol I&O Manual INTEGRUS Tech ST
Transmission Protocol Integrus Receiver DCN Next Generation DCN system IntegrusRadiator Integrus Trans-mitter Up to 32 Channels Interpreters desks 6ch. IntegrusRadiator Integrus Receiver Audio sources IntegrusRadiator IntegrusRadiator Integrus Receiver Integrus Receiver Diagram Digital Infra-Red Transmission System Integrus Charging equipment INTEGRUS Tech ST
Infra Red Radiation • Based on transmission by modulated infra-red radiation. • Has a wavelength just above that of visible light. • Like visible light, it is reflected from hard surfaces, yet passes through translucent materials such as glass. • Radiators are used to emission infra-red light with a wavelength of 870 nm. INTEGRUS Tech ST
% 100 75 1 50 25 4 5 3 2 0 400 500 600 700 800 870 900 1000 nm Daylight spectrum Intra-Red radiator Sensitivity of the human eye 1 3 2 Sensitivity of the Infra-Red diode at the receiver 4 Sensitivity of the Infra-Red diode at the receiver with daylight filter 5 Infra- Red spectrum in relation to other spectra INTEGRUS Tech ST
Audio Channel 01 A/D Conversion & Compression Protocol Creation & Modulation 4x Carrier (to IR Radiator) 4x Audio Channel 04 A/D Conversion & Compression Signal Processing • The Integrus system uses high frequency carrier signals (typically 2-8 MHz) to prevent interference problems with modern light sources. • The transmission system converts analogue audio signals to digital frequency modulated infra-red light. • The digital audio processing guarantees a constant high audio quality. • Receivers pick up the digital frequency modulated infra-red signal and convert it back to an audio signal for a headphone. INTEGRUS Tech ST
Signal Processing main steps • A/D conversion - Each analogue audio channel is converted to a digital signal. • Compression - To increase the amount of digital information. • Protocol Creation - Groups of four digital signals are combined into one digital information stream. Fault algorithm information is added for fault detection and correction. • Modulation - A high frequency carrier signal is phase-modulated with the digital information stream. • Radiation – Up to 8 modulated carrier signals are combined and sent to the infra-red radiators, which convert the carrier signals to modulated infra-red light. • De-Modulation – a reversed process is used in the IR receivers to convert the modulated infra-red light to separate analogue audio channels. INTEGRUS Tech ST
Audio Channel Quality modes • Up to four different audio channel quality modes: • Mono, standard quality, maximum 32 channels of 10kHz • Mono, premium quality, maximum 16 channels of 20kHz • Stereo,standard quality, maximum 16 channels of 2x 10kHz • Stereo,premium quality, maximum 8 channels of 2x 20kHz • The Standard quality mode uses less bandwidth and can be used for transmitting speech. • For music the Premium quality mode is advisable. INTEGRUS Tech ST
Carriers and Channels • Up to 8 different carrier signals (depending on the transmitter type) can be transmit. Each carrier can contain up to 4 different audio channels. • The maximum number of channels per carrier is dependent on the chosen quality modes. • Per carrier a mix of channels with different quality modes is possible, as long as the total available bandwidth is not exceeded. INTEGRUS Tech ST
Carriers and Channels This table lists all possible channel combinations per carrier: Mono SQ Mono PQ Stereo SQ Stereo PQ Carrier INTEGRUS Tech ST
Carrier Allocation Carriers and Channels • The data is digitally modulated onto the carriers. The modulation method used is DQPSK (Differential Quadrature Phase Shift Keying) with coherent detection at the receiver. • The information is carried by the phase changes. INTEGRUS Tech ST
Audio Encoding and Quality • All audio sent by the transmitter, is compressed by a sub-bandAPCM (Adaptive Pulse Code Modulation) encoder. • System Audio Performance Measured from the audio input of an LBB4503 to the headphone output of an LBB4540 • Audio frequency response: Standard Quality mode………………... : 20 Hz to 10 kHz (-3 dB) Premium Quality…………….…………. : 20 Hz to 20 kHz (-3 dB) • Total harmonic distortion at 1kHz … : < 0.05 % • Crosstalk attenuation at 4 kHz….…. : > 80 dB • Dynamic range……………………….. : > 80 dB • Weighted signal-to-noise ratio…….. : > 80 dB(A) I&O Manual INTEGRUS Tech ST
Transmission Protocol • Protocol and modulation technique :according to IEC 61603 part 7 • Carrier structureEach carrier contains: • synchronization information • audio slots • data slot(s) • A Reed-Solomon RS coder is applied to protect the audio and data information for transmission errors. INTEGRUS Tech ST
Audio slot B RS parity data Audio slot A SQ SQ RS parity data Audio slot B Audio slot A SQ SQ SYNC RS frame 0 RS frame 1 RS frame 2 RS frame 3 RS frame 4 RS frame 5 1 super frame Transmission Protocol • With four Standard Quality channels INTEGRUS Tech ST
Audio slot B RS parity data Audio slot A PQ RS parity data Audio slot B Audio slot A PQ SYNC RS frame 0 RS frame 1 RS frame 2 RS frame 3 RS frame 4 RS frame 5 1 super frame Transmission Protocol • With two Premium Quality channels INTEGRUS Tech ST
System Technology End of section INTEGRUS Tech ST