Abstract: A wireless communication network has a plurality of child nodes and a control node. Communication is carried out by using infrared or the like. The child nodes have modulators and demodulators. The modulators include modulation sets comprising the same kind of a modulation system having different multiple value formation levels. The modulation system is selected from the modulation sets in accordance with the communication distance or the communication speed necessary for the child node. Data is transmitted at high speed by precisely and simply restricting multiple paths. A delay amount of multiple paths whereby the S/N ratio remains equal both where multiple paths are present and where they are not present, is calculated; and a reflection position constituting the delay amount also is calculated.

Abstract: An audio signal transmitting apparatus including, an audio transmission signal generating unit for adding an error correction signal to a digital audio signal and encoding and interleaving the result to generate an audio transmission signal; a continuous signal generating unit which generates a continuous signal by repeating the digital control signal to be used for the reproduction of the digital audio transmission signal a predetermined number of times; a multiplexing unit for multiplexing the audio transmission signal and the continuous signal to generate a multiplexed signal; a modulated signal generating unit for modulating the multiplexed signal by a predetermined digital modulation method to generate a modulated signal within a predetermined frequency band; and an optical signal transmitting unit for converting the modulated signal to an optical transmission signal and transmitting the same.

Abstract: A surface acoustic wave convolver includes first and second interdigital electrodes for exciting surface acoustic waves and an output electrode for detecting the surface acoustic waves to extract a convolution output as an electrical signal, the first and second interdigital electrodes and the output electrode being formed on a piezoelectric or electrostrictive substrate.