Abstract: A modulation apparatus is disclosed that enables significant improvements in signal transmission rate in a limited frequency band as compared with conventional modulation schemes. The modulation apparatus has first and second frequency-increasing single side band (SSB) modulators. The modulators are configured to have respective carrier frequencies with a difference by a frequency corresponding to the symbol frequency (i.e. fundamental frequency of the input symbol). An adder combines a lower side band (LSB) signal obtained from the SSB modulator set for a higher carrier frequency, and an upper side band (USB) signal obtained from the SSB modulator set for a lower carrier frequency to obtain a modulation signal.

Abstract: Linear elements 101a to 101d are conductors, which have the element length equivalent to half a wavelength, have been placed so that they may draw a diamond shape. Delay elements 102a and 102b are bent conductors, which have a total length equivalent to one fourth wavelength and a length L2 equivalent to one eighth. The linear elements 101a and 101c are connected one another via the delay element 102a, while the linear elements 101b and 101d are connected one another via the delay element 102b. A feeding section 103 is connected to each of the ends of the linear elements 101a and 101b for feeding power to them. Between the tips of the linear elements 101c and 101d, a gap with a length L3 is left. A reflector 104 has been placed at a distance h from a diamond-shape antenna with delay elements along the ?Z axis, the distance h being equivalent to 0.42 wavelength.

Abstract: A modulation apparatus is disclosed that enables great improvements in signal transmission rate in a limited frequency band as compared with conventional modulation schemes. Modulation apparatus 100 has first and second frequency-increasing SSB modulators 110 and 120. The modulators 110 and 120 are configured to have respective carrier frequencies with a difference by a frequency corresponding to the reciprocal of the symbol rate (i.e. fundamental frequency of the input symbol). Adder 130 combines a LSB signal obtained from the SSB modulator 120 set for a higher carrier frequency, and a USB signal obtained from the SSB modulator 110 set for a lower carrier frequency to obtain a modulation signal.

Abstract: First and second quadrature modulators 109, 110 carry out quadrature modulation on Nyquist signals given a delay difference corresponding to 2/4 of their respective symbol periods using a cosine wave having a frequency corresponding to an odd-number multiple of the basic frequency of each Nyquist signal as a carrier. Third quadrature modulator 113 carries out quadrature modulation on the modulated signal obtained from first quadrature modulator 109 and the modulated signal obtained from second quadrature modulator 110 using a carrier having a predetermined frequency. Thus, it is possible to obtain modulated signals with four Nyquist signals allocated in a 1-symbol period T without any interference with one another.

Abstract: A dielectric substrate 101 is a square substrate having a dielectric constant ?r, thickness t and length per side of Wd. A grounding conductor 102 is provided on one side of the dielectric substrate 101 in the same shape as the dielectric substrate 101. An MSA element 103 is formed of square copper foil having a length per side of Wp in the center of the other side of the dielectric substrate 101. Mono-pole antennas 104a to 104d are copper wires having a diameter D and length L and are spaced uniformly on diagonals of the MSA element 103 and disposed perpendicular to the dielectric substrate 101. The MSA element 103 or mono-pole antennas 104a to 104d is selectively fed, whichever has higher reception power. When the mono-pole antennas 104a to 104d are selected, the phases and amplitudes of the respective elements are controlled.

Abstract: Provided are switch 125 which makes N copies of each of M signals obtained in a transmission system, and thereby forms M×N channel signals, channel processing sections 126-1 to 126-MN which add correlated instantaneous variations and short-term variations corresponding to arrangements of transmission and reception antennas to the M×N channel signals, respectively, and selection combining section 128 which selectively combines M channel signals repeatedly among the M×N channel signals provided with channel variations to form N signals.

Abstract: An output signal of digital baseband processing section 41 is directly input, and receiver noise adding section 103 adds receiver noise simulating the SNR variation due to fading to the signal while keeping an entire signal level constant in single-path channel simulation, while in multipath channel simulation, instantaneous variation adding section 101 and short-term interval variation adding section 102 add only amplitude variations to respective signals of paths, and automatic gain control section 104 keeps a level of the path-combined signal constant, whereby it is possible to evaluate channel performance of digital baseband processing section 41 without waiting for development of radio circuit 53, i.e. without an AGC circuit and AFC circuit in reception system 50.

Abstract: Linear elements 101a to 101d are conductors, which have the element length equivalent to half a wavelength, have been placed so that they may draw a diamond shape. Delay elements 102a and 102b are bent conductors, which have a total length equivalent to one fourth wavelength and a length L2 equivalent to one eighth. The linear elements 101a and 101c are connected one another via the delay element 102a, while the linear elements 101b and 101d are connected one another via the delay element 102b. A feeding section 103 is connected to each of the ends of the linear elements 101a and 101b for feeding power to them. Between the tips of the linear elements 101c and 101d, a gap with a length L3 is left. A reflector 104 has been placed at a distance h from a diamond-shape antenna with delay elements along the ?Z axis, the distance h being equivalent to 0.42 wavelength.