Abstract: A communication system includes: a specific node; and a plurality of nodes that are installed at fixed positions and perform ad hoc wireless communication with the specific node. The nodes each include a link quality evaluating unit, an upstream route constructing unit, a communicating unit, and a downstream route constructing unit. The link quality evaluating unit performs route evaluation using a hello frame based only on a track record of reception of the hello frame in order to perform upstream communication toward the specific node to form a network. The upstream route constructing unit constructs an upstream route based on the route evaluation. The communicating unit performs upstream communication toward the specific node on a regular basis with a predetermined frequency. The downstream route constructing unit constructs a downstream route from the specific node based on a route in the upstream communication toward the specific node.

Abstract: A wireless communication apparatus includes: a first signal communicating unit that receives a first signal of a first wireless communication system or transmits, based on allocation information of a wireless communication resource which information is transmitted in a predetermined cycle, the first signal of the first wireless communication system; a second signal communicating unit that receives or transmits a second signal of a second wireless communication system different from the first wireless communication system; and a controller that restricts the first signal communicating unit to transmit the first signal of the first wireless communication system using a wireless communication resource allocated by the allocation information while the second signal communicating unit transmits or receives the second signal.

Abstract: A local carrier wave output from a synthesizer to quadrature demodulators is multiplied by an offset that makes a frequency shift by an integer number of subcarriers in units of sub-carrier bands. The offset is set to a value obtained by multiplying the number sequentially counted up from 0 to the number of unused sub-carriers included in guard tones in a signal band by the bandwidth of a sub-carrier. By shifting the frequency of the local carrier wave at the time of quadrature demodulation with the offset, the SNR of a baseband signal is prevented from being constantly degraded by a frequency characteristic possessed by the circuit of a receiver in a particular sub-carrier signal. Especially, by preventing a pilot signal from being constantly degraded, the signal can be received with higher accuracy.

Abstract: A base station includes an identifying unit that identifies a group to which a mobile station that is to start communication belongs; a determining unit that determines a second pilot signal, which is allocated to the group identified by the identifying unit, to be a pilot signal for communication with the mobile station; and a transmitting unit that transmits information for identifying the second pilot signal to the mobile station by using a first pilot signal determined beforehand for each group as a pilot signal for notifying the information.

Abstract: A communication apparatus includes an acquiring unit that acquires wireless cost for each path to other communication apparatuses in an ad hoc network to which the communication apparatus belongs; an accumulating unit that accumulates wireless cost for each path, acquired at different times by the acquiring unit; a determining unit that determines a priority level for each path, based on time correlations among the paths in terms of the wireless cost accumulated by the accumulating unit; and a communicating unit that communicates with the other communication apparatuses by preferentially using a path of a relatively high priority level.

Abstract: The present invention discloses a method for estimating quality of a link in a broad-band wireless communication system. The method includes: calculating quality indicators of sub-carriers in an input signal of a receiver of the system; clipping the quality indicators of the sub-carriers; and averaging the clipped quality indicators of the sub-carriers to obtain an average value as an estimation result of an effective quality indicator of the link. The present application also discloses an apparatus for estimating quality of a link in a broad-band wireless communication system, an adaption method and apparatus for a link in a broad-band wireless communication system. The methods and apparatus of the present invention can achieve relatively low calculation complexity and high accuracy.

Abstract: A radio communication method for performing a radio communication between a first and second movable base station apparatuses and a subordinate terminal apparatus respectively, the method including: transmitting and receiving configuration information relating radio resource and load information relating the subordinate terminal apparatus in the first and second base station apparatuses respectively, via the terminal apparatus located in an overlapped communicable range of the first and second base station apparatuses, when the first and second base station apparatuses perform radio communication using the same radio resource, by the first and second base station apparatuses respectively; and performing interference control based on the configuration information and the load information, by the first and second base station apparatuses respectively.

Abstract: A local carrier wave output from a synthesizer to quadrature demodulators is multiplied by an offset that makes a frequency shift by an integer number of subcarriers in units of sub-carrier bands. The offset is set to a value obtained by multiplying the number sequentially counted up from 0 to the number of unused sub-carriers included in guard tones in a signal band by the bandwidth of a sub-carrier. By shifting the frequency of the local carrier wave at the time of quadrature demodulation with the offset, the SNR of a baseband signal is prevented from being constantly degraded by a frequency characteristic possessed by the circuit of a receiver in a particular sub-carrier signal. Especially, by preventing a pilot signal from being constantly degraded, the signal can be received with higher accuracy.

Abstract: A sync detector includes a correlation computing unit configured to receive signal values corresponding to respective sample points and to compute auto-correlation of the received signal values between sample points of interest and sample points that are situated at a distance equal to a constant number of sample points from the sample points of interest, a correlation value synthesizing unit configured to receive auto-correlation values corresponding to respective sample points obtained by the correlation computing unit and to synthesize the auto-correlation values with respect to at least two sample points among sample points that are spaced apart by the constant number of sample points thereby to compute a synthesized correlation value, and a peak-point detecting unit configured to detect a position of a sample point corresponding to a largest synthesized correlation value among synthesized correlation values corresponding to respective sample points obtained by the correlation value synthesizing unit.

Abstract: A wireless communication apparatus includes: a first signal communicating unit that receives a first signal of a first wireless communication system or transmits, based on allocation information of a wireless communication resource which information is transmitted in a predetermined cycle, the first signal of the first wireless communication system; a second signal communicating unit that receives or transmits a second signal of a second wireless communication system different from the first wireless communication system; and a controller that restricts the first signal communicating unit to transmit the first signal of the first wireless communication system using a wireless communication resource allocated by the allocation information while the second signal communicating unit transmits or receives the second signal.

Abstract: The present invention discloses a method for estimating quality of a link in a broad-band wireless communication system. The method includes: calculating quality indicators of sub-carriers in an input signal of a receiver of the system; clipping the quality indicators of the sub-carriers; and averaging the clipped quality indicators of the sub-carriers to obtain an average value as an estimation result of an effective quality indicator of the link. The present application also discloses an apparatus for estimating quality of a link in a broad-band wireless communication system, an adaption method and apparatus for a link in a broad-band wireless communication system. The methods and apparatus of the present invention can achieve relatively low calculation complexity and high accuracy.

Abstract: A communication apparatus includes an acquiring unit that acquires wireless cost for each path to other communication apparatuses in an ad hoc network to which the communication apparatus belongs; an accumulating unit that accumulates wireless cost for each path, acquired at different times by the acquiring unit; a determining unit that determines a priority level for each path, based on time correlations among the paths in terms of the wireless cost accumulated by the accumulating unit; and a communicating unit that communicates with the other communication apparatuses by preferentially using a path of a relatively high priority level.

Abstract: A radio communication method for performing a radio communication between a first and second movable base station apparatuses and a subordinate terminal apparatus respectively, the method including: transmitting and receiving configuration information relating radio resource and load information relating the subordinate terminal apparatus in the first and second base station apparatuses respectively, via the terminal apparatus located in an overlapped communicable range of the first and second base station apparatuses, when the first and second base station apparatuses perform radio communication using the same radio resource, by the first and second base station apparatuses respectively; and performing interference control based on the configuration information and the load information, by the first and second base station apparatuses respectively.

Abstract: A base station includes an identifying unit that identifies a group to which a mobile station that is to start communication belongs; a determining unit that determines a second pilot signal, which is allocated to the group identified by the identifying unit, to be a pilot signal for communication with the mobile station; and a transmitting unit that transmits information for identifying the second pilot signal to the mobile station by using a first pilot signal determined beforehand for each group as a pilot signal for notifying the information.

Abstract: A radio communication method in a radio communication system in which radio communication is performed between a radio communication base station apparatus and a radio communication mobile station apparatus, including: transmitting, by the radio communication mobile station apparatus, an implementation loss value of the radio communication mobile station apparatus to the radio communication base station apparatus.

Abstract: A local carrier wave output from a synthesizer to quadrature demodulators is multiplied by an offset that makes a frequency shift by an integer number of subcarriers in units of sub-carrier bands. The offset is set to a value obtained by multiplying the number sequentially counted up from 0 to the number of unused sub-carriers included in guard tones in a signal band by the bandwidth of a sub-carrier. By shifting the frequency of the local carrier wave at the time of quadrature demodulation with the offset, the SNR of a baseband signal is prevented from being constantly degraded by a frequency characteristic possessed by the circuit of a receiver in a particular sub-carrier signal. Especially, by preventing a pilot signal from being constantly degraded, the signal can be received with higher accuracy.

Abstract: A sync detector includes a correlation computing unit configured to receive signal values corresponding to respective sample points and to compute auto-correlation of the received signal values between sample points of interest and sample points that are situated at a distance equal to a constant number of sample points from the sample points of interest, a correlation value synthesizing unit configured to receive auto-correlation values corresponding to respective sample points obtained by the correlation computing unit and to synthesize the auto-correlation values with respect to at least two sample points among sample points that are spaced apart by the constant number of sample points thereby to compute a synthesized correlation value, and a peak-point detecting unit configured to detect a position of a sample point corresponding to a largest synthesized correlation value among synthesized correlation values corresponding to respective sample points obtained by the correlation value synthesizing unit.

Abstract: A protection panel is provided that enhances the color quality and/or contrast of a rear projection television set. The protection panel has a spectral transmittance that peaks at dominant wavelengths of red, green, and blue light, and that is reduced at wavelengths between red and green light and between green and blue light. The spectral transmittance at the dominant wavelengths is between sixty and eighty percent. Preferably, the spectral transmittance at the wavelengths between red and green light and between green and blue light are at least five percent less than at the dominant wavelengths. In addition, the spectral transmittance at a dominant wavelength of red light is about five percent less than at a dominant wavelength of blue light to reduce blue color saturation.