93results about How to "Improve reception characteristics" patented technology

One of plurality of transmission terminals connected to a transmission filter and a receiving terminal connected to a receiving filter is a balanced type terminal, and another is an unbalanced type terminal. The transmission filter and the receiving filter includes surface acoustic wave resonators or film bulk acoustic resonators. The balanced type terminal is connected to a longitudinal mode coupled surface acoustic wave filter.

Provided are a wireless communication system and a method for enabling measurement of amount of phase fluctuation before and after frequency hopping and improving the reception characteristic. A mobile station (301) transmits a plurality of reference signals upon placing the reference signals in temporally spaced-apart relation in at least one of information transmission units (one or a plurality of time slots) wirelessly transmitted in conformity with a hopping period, and a base station (302) receives an information transmission unit that has been transmitted from the mobile station (301) and, if this information transmission unit is one that includes a plurality of the reference signals, obtains a phase fluctuation from the plurality of reference signals and obtains a frequency deviation from the phase fluctuation.

An OFDM transmitter transmits an OFDM signal by a frame having a plurality of transmission symbol periods constituted of an effective symbol period for transmitting an information bit and a guard interval. The OFDM transmitter includes a guard interval length decider configured to decide a guard interval length in accordance with a feedback signal from an OFDM receiver; and a guard interval length changer configured to change a guard interval length in each transmission symbol period, in accordance with a decided guard interval length without changing a frame length.

Radio receiving apparatus includes antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the weight, and demodulator which demodulates the synthetic digital signal.

In a coherent optical receiver, a light intensity value of signal light providing an optimum reception state is determined when ideal signal light free from waveform distortion is used as the signal light in a state where local-oscillator light is turned on. A first amplitude value of an analog electrical signal corresponding to the signal light is stored in a storage section, wherein the first amplitude value is obtained at a time when the ideal signal light of the light intensity value determined is used as the signal light in a state where the local-oscillator light is turned off. Light intensity of the signal light is determined so as to make a second amplitude value equal to the first amplitude value, wherein the second amplitude value is an amplitude value of the analog electrical signal which is obtained at a time when actual signal light is used as the signal light in a state where the local-oscillator light is turned off.

planar antenna. The planar antenna of the present invention comprises: a linear antenna element (1) to be supplied with electric power; and loop parasitic antenna elements (2, 3) arranged in the vicinity of said linear antenna element (1), said linear antenna element and loop parasitic antenna elements are disposed on one side of the dielectric substrate (10). This simple arrangement provides a planar antenna with good circular polarization properties.

An encoding section (101) subjects an each predetermined error-detection unit of data to error-detection encoding. A multinary modulation section (102) disposes coded data included in error-detection units in one transmission unit and transmits the transmission unit. A first decoding section (114) decodes the received signal and detects an error, if any, in the decoded signal for each error-detection unit. A second decoding section (115) changes the likelihood of each bit on the basis of the result of the error detection by the first decoding section (114). Thus the ability of error correction of a signal multinary-modulated by using the high-accuracy likelihood is improved, thereby improving the transmission quality.

A radio receiver including a reception processing system that uses a discrete-time frequency conversion to acquire a signal having a sampling rate corresponding to a local frequency, wherein the reception characteristic is improved when the reception processing system is applied to a system having a wide reception channel band. The radio receiver (100) comprises a discrete-time frequency converting part (130) that uses a local frequency signal to sample a received signal in a discrete-time manner, thereby performing a frequency conversion and a thinning process to output a discrete-time analog signal of a sampling rate in accordance with the local frequency; an A / D converting part (150) that quantizes the discrete-time analog signal to a digital value to output a received digital signal; a channel selection filtering part (161) that uses a tap coefficient value to perform a digital filtering process of the received digital signal; and a frequency response characteristic correcting part (162) that generates the tap coefficient in accordance with the sampling rate.