Abstract: According to one embodiment, an ASK demodulator includes a rectifier, a first low-pass filter, a second low-pass filter, a comparator, and a threshold controller. The rectifier rectifies an ASK signal. The first low-pass filter outputs a signal corresponding to an envelope curve output from the rectifier. The second low-pass filter outputs an integrated signal of the signal output from the first low-pass filter. The comparator detects an output logic in accordance with comparison between the signal output from the first low-pass filter and a threshold obtained by adding a predetermined hysteresis width to the integrated signal output from the second low-pass filter. The threshold controller controls the threshold by setting the predetermined hysteresis width based on a direct current offset voltage caused by element dispersions of the comparator.

Abstract: According to one embodiment, an ASK demodulator includes a rectifier, a first low-pass filter, a second low-pass filter, a comparator, and a threshold controller. The rectifier rectifies an ASK signal. The first low-pass filter outputs a signal corresponding to an envelope curve output from the rectifier. The second low-pass filter outputs an integrated signal of the signal output from the first low-pass filter. The comparator detects an output logic in accordance with comparison between the signal output from the first low-pass filter and a threshold obtained by adding a predetermined hysteresis width to the integrated signal output from the second low-pass filter. The threshold controller controls the threshold by setting the predetermined hysteresis width based on a direct current offset voltage caused by element dispersions of the comparator.

Abstract: In a bidirectional transmission system including an I/O circuit, an I/O circuit, and a bidirectional transmission path which connects the circuits together, a variable impedance circuit is provided at an input end of the circuit connected to the transmission path. First transmission information (an output signal from the circuit) is sent from the circuit to the circuit via the transmission path as a voltage signal. Second transmission information (an impedance control signal from the variable impedance circuit) is sent from the circuit to the circuit via the transmission path as a voltage signal. The second transmission information is transmitted to the circuit as a change in the voltage signal which corresponds to a change in the circuit impedance Z of the variable impedance circuit.

Abstract: In a design of the printed circuit board design device, a signal wire name is affixed to each wiring of a circuit, thereby making it quite easy to go through confirmation works after the design works are thoroughly accomplished. The present invention aims at improving efficiency of works for affixing the signal wire name. For this purpose, the signal wire names are input for each desired area of the circuit. By taking full advantage of overlap of the area concerned, the signal wire names connected in serial form are affixed to one wiring. The candidates of the signal wire names to be affixed are tabulated as a list. After the signal wire names are affixed to each wiring of the circuit, the wiring can be retrieved and shown in visible display. In this case too, the candidates of the signal wire names to be retrieved can be tabulated as a list.

Abstract: A radio communication system which keeps to a minimum the number of slots which cannot be used due to interference from a neighboring base station, and which can increase the slot usage efficiency. A slot/frame setting unit for a base station extracts the slot/frame timing of a neighboring base station based on the reception output of a radio unit, and sets the communication frame by displacing it in such a way that two slots in the own base station do not coincide in time with a slot of the neighboring base station based on this timing. This setting ensures that there is always just a single slot which cannot be used when interference is detected.

Abstract: The present invention is directed to a radio communications apparatus with combining diversity in which received radio signals are weighted appropriately to reduce an error in demodulation and improve in communication quality. In the signal combining diversity radio communications apparatus, the digital reception signals of an intermediate frequency, output from the reception circuit, are demodulated by demodulation circuits into digital demodulation signals of the baseband. The digital demodulation signals are input to the multiplication circuits. The multiplication circuits multiply the digital demodulation signals by the weight coefficients, which are generated by weight coefficient generation circuits and corresponding to the digital demodulation signals, based on C/N ratio detection signals, in order to weight the digital demodulation signals. The weighted demodulation signals are added together by a digital addition circuit.