Alps Electric Co., Ltd.

Yukio Ohtaki

Toru Oyama

Takeo Suzuki

Kouta Iijima

Kazutoshi Kitada

A digital tuner unit receiving a digital signal in a reception channel having a predetermined bandwidth is connected at a subsequent stage of an antenna device containing radiation conductors and varactor diodes. A digital reception signal output from the digital tuner unit is input to a demodulation circuit and subjected to demodulation. An SP level detection unit of the demodulation circuit detects levels of a plurality of spread pilot signals in the bandwidth of the reception channel, and obtains a correction amount for a tuning voltage so that a level difference can be reduced to a predetermined value or less using the correction amount. The SP level detection unit reports the correction amount to an antenna tuning control unit so that the tuning voltage to be supplied to the antenna device can be corrected using the correction amount.

Digital signal receiver including wideband tunable antenna device

A first low-noise amplifier is connected to a first receiving processing unit through a first cable and a bypass circuit is provided in parallel to the first low-noise amplifier so as to bypass the first low-noise amplifier. In the case that the intensity of broadcasting signal is more than a predetermined value, when the C/N is more than a first predetermined value and less than a second predetermined value higher than the first predetermined value, the broadcasting signal is transmitted to the first cable through the first low-noise amplifier, and when the C/N is less than the first predetermined value or more than the second predetermined value, the broadcasting signal is not input to the first low-noise amplifier but transmitted to the first cable through the bypass circuit.

Vehicle-mounted receiving apparatus for reducing distortion, improving reception sensitivity, and saving power

An OFDM receiver has four antennas or more for receiving an OFDM modulated high frequency signal, and plural OFDM demodulators for inputting a baseband signal of a time domain thereto on the basis of the high frequency signal and outputting the baseband signal of a frequency domain, wherein the OFDM demodulators are arranged every plural antenna groups with two or more of the antennas as one group, and a signal is diversity-synthesized by a first phase shifter until the baseband signal of the time domain is inputted to each of the OFDM demodulators, and the baseband signal of the frequency domain is diversity-synthesized by a second phase shifter.

OFDM receiver for easily synchronizing base band signal

A delay equalizing unit includes a delay time calculating unit for calculating a plurality of delay times which differ from each other by short time periods and which include the delay time of the delayed wave with respect to the direct wave, so that an OFDM-modulated signal input to path correlation detectors is delayed by the plurality of delay times. A feedback unit causes the amplitude and phase of the negatively fed back direct wave to coincide with the amplitude and phase of the delayed wave input to an adding unit based on the largest of the path correlations, so that the negatively fed back direct wave is delayed by a designated delay time based on which the largest path correlation is determined.

OFDM receiving apparatus with reduced bit error rate after demodulation

A diversity receiving apparatus comprises a plurality of antennas, a plurality of receiving circuits connected to the plurality of antennas, respectively, an adding unit for adding reception signals output from the respective receiving circuits, and a plurality phase shifting units for making phases of the reception signals to be input into the adding unit equal. A level comparing unit, for comparing the levels of the reception signals output from the respective receiving circuits, is provided. Phases of reception signals other than a maximum-level reception signal are controlled so as to have the same phase as the phase of the maximum-level reception signal, and the phase-controlled signals are input into the adding unit.

Diversity receiving apparatus capable of preventing reduction of C/N ratio

A receiver has an adder for output intermediate-frequency signals of a plurality of receiving blocks, a demodulator for an added intermediate-frequency signal, adjustable reference-signal generator for supplying phase-shifted reference signals to the PLL circuits of the plurality of receiving blocks, and a plurality of switches. The switches are controlled when power is first supplied to the receiver such that the frequency-divided reference signals to the PLL circuits are in phase with one another. The adjustable reference-signal generator, upon tuning on power, is set in the phase-shift adjusted state stored immediately before previously turning off the power.

Receiver capable of receiving radio signals in a preferred state at all times

A diversity reception device includes a plurality of antennas. A plurality of receiver circuits are connected to the corresponding antennas. An adder adds the received signals output from the receiver circuits. Phase shifters allow the received signals to be input into the adder in phase with each other. A level comparator unit compares the levels of the received signals output from the receiver circuits. A level variable unit is interposed between each of the receiver circuits and the adder, and is controlled by the level comparator unit. Each of the received signals other than the received signal having the maximum level is relatively attenuated by the corresponding level variable unit in accordance with the difference of the level of the received signal from the maximum level before being input into the adder.

Diversity reception device outputting maximized C/N ratio of synthesized signal

An antenna receiver includes a plurality of mixers for frequency-converting signals received by a plurality of antennas into intermediate-frequency signals; a plurality of local oscillators, which correspond to the plurality of mixers and which supply local oscillation signals having the same frequency to the mixers; a plurality of PLL circuits, which correspond to the plurality of local oscillators and which set the frequency of the local oscillation signals; and an adder for adding the intermediate-frequency signals output from the mixers. The phases of reference signals supplied to the PLL circuits can be changed independently from each other.

Growing community of inventors

Fukushima-ken, Japan

Yukio Ohtaki