摘要:
The invention provides an automatic amplitude equalizer for compensating an amplitude characteristic of an input signal, wherein a control signal for equalizing an inclination amplitude distortion of an input signal is detected making use of a pair of digital demodulated signals to compensate for the amplitude characteristic of the input signal with a high degree of accuracy and which can be constructed with a reduced circuit scale and at a reduce cost. The automatic amplitude equalizer includes a first-order inclination amplitude equalization section for compensating for an amplitude characteristic of an input signal in accordance with a first-order inclination amplitude characteristic, and a control section for discriminating a direction of variation of a value of a first one of a pair of digital demodulated signals originating from the input signal, detecting error information from the other, second one of the digital demodulated signals which is orthogonal to the first signal, and outputting a control signal for the first-order inclination amplitude equalization section based on a correlation between the error information and the direction of variation of the value of the first signal.
摘要:
A cross polarization interference canceler includes a digital conversion circuit for subjecting a demodulated signal of one channel to an analog-to-digital conversion out of two channels which are independently formed using carriers having the same frequency but having planes of polarization which are mutually orthogonal. An interference cancelling circuit cancels interference caused by the other channel out of the two channels, with respect to the demodulated signal which is digitally converted by the digital conversion circuit. An integrator circuit performs an integration process with respect to the demodulated signal which is digitally converted by the digital conversion circuit so as to provide negative feedback to the digital conversion circuit.
摘要:
A communication system includes a first communication apparatus and a second communication apparatus. The second communication apparatus transmits different signals from first and second antennas, and first and second antennas of the first communication apparatus receive the signals, respectively. An angle formed by a first line connecting the first communication apparatus and the first antenna of the second communication apparatus and a second line connecting the first communication apparatus and the second antenna of the second communication apparatus is set to be equal to or smaller than 180 degrees. A distance between the first and second antennas of the first communication apparatus is set to a specified value, which is determined by a signal wavelength and the angle formed by the first line and the second line.
摘要:
A mobile station that performs wireless communication through a base station, includes a first connection setup request unit configured to make a first connection setup request for an emergency call and a normal call when communication performed in the communication region of the base station is in a congestion state, the emergency call and the normal call using a signal sequence that corresponds to a sequence number of a connection setup request signal used when communication performed in a communication region of the base station is in a normal state, and a second connection setup request unit configured to make a second connection setup request for another one of the emergency call and the normal call different from the first connection setup request, using a generated-signal sequence generated from the sequence number, when communication performed in the communication region of the base station is in the congestion state.
摘要:
A frequency control device receiving a signal transmitted from each of a plurality of mobile stations, the frequency control device includes a first detecting unit to detect a frequency deviation generated from the signal, a second detecting unit to acquire information about at least a current position or movement of each of the mobile stations as classification information, and a classifying unit to classify mobile stations estimated to be moving in a same moving direction with a same moving speed as a first mobile station based on the classification information. The frequency control device includes a first calculating unit to calculate a first frequency deviations of a signal received from the first mobile station, and a compensation unit to compensate the frequency deviation of the signal received from the first mobile station based on the first frequency deviation.
摘要:
In a calibration apparatus, which calibrates the phases of main signals input to each of the antenna elements of an array antenna, a calibration signal generation portion generates calibration signals, which are combined with main signals. An RF switch alternately inputs to a wireless receiving portion the signals radiated from other antenna elements via a first antenna element, and the signals radiated from other antenna elements via a second antenna element, and causes demodulation. The calibration detection portion detects calibration signals from the demodulated signals, and the weight generation portion uses the detected calibration signals to calculate calibration weights, which are set in the phase shifter, to control the phases of main signals for input to each antenna element.
摘要:
Sample signals P0(0) to P0(N−1) are input for each symbol of a multiplexed transmission sample or transmission chip. The sum of a particular pair of sample signals (for example, a pair of P0(0) and P0(N/2)) is obtained by an adder for each pair of sample signals, and a signal the power of which is halved by attenuating the sum with an attenuator is generated and output as a dispersion signal P1(N/2). Additionally, a difference between the pair of the sample signals is obtained by a subtractor, and a signal the power of which is halved by attenuating the difference with an attenuator is generated and output as a dispersion signal P1(0). The dispersion signals P1(0) and P1(N/2) are made to respectively correspond to first and second subsymbols, which are configured by partitioning the symbol.
摘要:
The disclosed radio frequency signal transmitting and receiving apparatuses compensate for phase and amplitude differences without detecting sync timing of a calibration signal. The radio frequency signal receiving apparatus consists of two or more antennas, radio frequency signal receiving units each being connected to an antenna, a calibration signal generating unit that generates the calibration signal having a cycle different from the cycle of a spread code, a radio frequency signal transmitting unit that converts the calibration signal into a radio frequency signal, directional couplers that add a radio frequency signal received by the respective antennas and the calibration signal in the radio frequency, a delaying unit that delays a baseband signal from the first radio frequency signal receiving unit, a correlation detecting unit that detects correlation between the output of the delaying unit and the baseband signal from the second radio frequency signal receiving unit, a weight generating unit, and a complex multiplier that compensates for the phase and gain differences due to the radio frequency signal receiving units based on the output of the correlation detecting unit.
摘要:
A signal separating unit separates an input signal into a first branch signal and a second branch signal in such a manner that, as the amplitude of the input signal decreases, the amplitude of the first branch signal and the second branch signal decreases and the difference between a phase of the first branch signal and a phase of the second branch signal increases and, as the amplitude of the input signal increases, the amplitude of the first branch signal and the second branch signal increases and the difference between the phase of the first branch signal and the phase of the second branch signal decreases. An amplifier amplifies the first branch signal. Another amplifier amplifies the second branch signal. A combining unit combines signals that are output from the amplifiers together, thereby generating an output signal.
摘要:
A wireless communication method executed by a wireless communication system including a relay apparatus, a first wireless communication apparatus, and a second wireless communication apparatus includes the following operations. Upon receiving a wireless signal from the first wireless communication apparatus, the relay apparatus adds advice information, which indicates that the wireless signal has been relayed, to the received wireless signal. The relay apparatus transmits the wireless signal added the advice information thereto to the second wireless communication apparatus. The second wireless communication apparatus detects the advice information to determine whether the wireless signal has been relayed.