Abstract: Provided is an OFDM reception apparatus that can reduce, even in an environment where the influence of noises is strong, this influence of the noises, thereby improving the precision of detecting a carrier frequency error. In this apparatus, a filtering unit (151) receives received signals each including a short preamble (STF) in which a plurality of pilot subcarriers are intermittently arranged in the frequency domain and repeatedly arranged in the time domain, and the filtering unit (151) attenuates the frequency components between respective two adjacent ones of the plurality of pilot subcarriers in the frequency domain. A correction unit (154) corrects a carrier frequency error of the received signal on the basis of the signals of the plurality of pilot subcarriers having passed through the filtering unit (151).

Abstract: A preamble generating unit generates first and second synchronization preambles having different numbers of subcarriers. A transmission signal generating unit generates an OFDM transmission signal through time-division multiplexing by using the generated first and second synchronization preambles. A transmission RF unit converts the generated OFDM transmission signal into a radio-frequency OFDM signal and transmits the radio-frequency OFDM signal. The preamble generating unit adds a predetermined dummy period between the first synchronization preamble and the second synchronization preamble.

Abstract: An OFDM receiver apparatus (100) receives a signal that includes an STF having a plurality of pilot subcarriers and a plurality of null subcarriers that are alternately arranged at predetermined frequency intervals in a transmission band and that includes a data part that is time-multiplexed with the STF. A null carrier extraction unit (151) extracts a plurality of null subcarrier frequency signals from the received signal. A power calculation unit (152) detects, based on the levels of the extracted signals, the interference levels of the plurality of subcarriers in the transmission band. A soft decision unit (112) uses the reliability of the plurality of subcarriers, which is calculated based on the detected interference levels, to perform a soft decision of a demodulated signal of the received data part. An error correction unit (113) performs, based on the result of the soft decision, an error correction, thereby reconstructing the data.

Abstract: An OFDM receiver apparatus (100) receives a signal that includes an STF having a plurality of pilot subcarriers and a plurality of null subcarriers that are alternately arranged at predetermined frequency intervals in a transmission band and that includes a data part that is time-multiplexed with the STF. A null carrier extraction unit (151) extracts a plurality of null subcarrier frequency signals from the received signal. A power calculation unit (152) detects, based on the levels of the extracted signals, the interference levels of the plurality of subcarriers in the transmission band. A soft decision unit (112) uses the reliability of the plurality of subcarriers, which is calculated based on the detected interference levels, to perform a soft decision of a demodulated signal of the received data part. An error correction unit (113) performs, based on the result of the soft decision, an error correction, thereby reconstructing the data.

Abstract: Provided is an OFDM reception apparatus that can reduce, even in an environment where the influence of noises is strong, this influence of the noises, thereby improving the precision of detecting a carrier frequency error. In this apparatus, a filtering unit (151) receives received signals each including a short preamble (STF) in which a plurality of pilot subcarriers are intermittently arranged in the frequency domain and repeatedly arranged in the time domain, and the filtering unit (151) attenuates the frequency components between respective two adjacent ones of the plurality of pilot subcarriers in the frequency domain. A correction unit (154) corrects a carrier frequency error of the received signal on the basis of the signals of the plurality of pilot subcarriers having passed through the filtering unit (151).

Abstract: A preamble generating unit generates first and second synchronization preambles having different numbers of subcarriers. A transmission signal generating unit generates an OFDM transmission signal through time-division multiplexing by using the generated first and second synchronization preambles. A transmission RF unit converts the generated OFDM transmission signal into a radio-frequency OFDM signal and transmits the radio-frequency OFDM signal. The preamble generating unit adds a predetermined dummy period between the first synchronization preamble and the second synchronization preamble.

Abstract: In a Viterbi decoding apparatus, deterioration in error correcting capability before and after a terminated code is controlled. A termination timing detection unit (103) detects a termination timing of a Viterbi code, a compulsion generation unit (105) generates a compulsion value so as to pass a specific path at the termination timing and timings before and after the termination timing, and the compulsion value is set on a traceback pointer (106). Therefore, even when the decoding state of a code before termination is degraded, decoding of a next code can be carried out without being affected by the degradation, thereby improving error correcting capability.

Abstract: There is provided a receiving apparatus (1) that comprises; a receiving unit (4) for receiving a frequency division multiplexing signal to output a receiving signal; a first demodulating unit (7) for demodulating a receiving signal based on 1 segment broadcasting and 3 segment broadcasting to output a first carrier; a second demodulating unit (8) for demodulating a receiving signal based on the 1 segment broadcasting to output a second carrier; a judging unit (9) for judging whether a receiving signal is the 1 segment broadcasting or the 3 segment broadcasting; and a combining/selecting unit (10) for combining or selecting the first carrier and the second carrier. In case of the 1 segment broadcasting, the combining/selecting unit (10) combines or selects the first carrier and the second carrier. In case of the 3 segment broadcasting, the combining/selecting unit (10) selects the first carrier.

Abstract: A fluid sealing mechanism for sealing fluid being fed into a fluid pressure pocket formed between sliding surfaces which are formed on the opposing surfaces of an article being supported and a support for supporting the article, wherein a ring groove being fitted with a resilient ring for sealing fluid is made in the sliding surface of the support. Under a state where a regulation ring for preventing the resilient ring from jumping out of the ring groove is fitted over the re-silient ring, the regulation ring is fitted in the ring groove along with the resilient ring. When the fluid fed into the fluid pressure pocket reaches a specified pressure, the regulation ring comes into pressure contact with the sliding surface of the support along with the resilient ring, thus preventing the resilient ring from jumping out.

Abstract: In a Viterbi decoding apparatus, deterioration in error correcting capability before and after a terminated code is controlled. A termination timing detection unit (103) detects a termination timing of a Viterbi code, a compulsion generation unit (105) generates a compulsion value so as to pass a specific path at the termination timing and timings before and after the termination timing, and the compulsion value is set on a traceback pointer (106). Therefore, even when the decoding state of a code before termination is degraded, decoding of a next code can be carried out without being affected by the degradation, thereby improving error correcting capability.

Abstract: A fluid sealing mechanism for sealing fluid being fed into a fluid pressure pocket formed between sliding surfaces which are formed on the opposing surfaces of an article being supported and a support for supporting the article, wherein a ring groove being fitted with a resilient ring for sealing fluid is made in the sliding surface of the support. Under a state where a regulation ring for preventing the resilient ring from jumping out of the ring groove is fitted over the re-silient ring, the regulation ring is fitted in the ring groove along with the resilient ring. When the fluid fed into the fluid pressure pocket reaches a specified pressure, the regulation ring comes into pressure contact with the sliding surface of the support along with the resilient ring, thus preventing the resilient ring from jumping out.

Abstract: In a static pressure table device wherein an annular recess is formed in one of confronting surfaces of a stationary bed and a rotary table thereon, and static pressure oil is supplied to the recess for rotatingly support the table on the bed, a static pressure gap formed between the confronting surfaces of the bed and table is constructed to gradually or stepwisely increase toward the outer periphery of the device. As a result, the viscosity resistance of the pressure oil is decreased toward the outer periphery and heat generation is reduced in the outer peripheral region, whereby a uniform temperature distribution of the table becomes possible with resultant reduced thermal deformation of the table so that the table can be rotated at high speed.

Abstract: A control system for effecting ultra-precision temperature control for a controlled system having large load fluctuations or including a dead time component. A control unit (5) instructs a high-precision PID temperature controller (10) to renew and correct a control target value T.sub.0,NEW for the supply fluid temperature T.sub.0 only by a temperature difference .DELTA.T=T.sub.C -T.sub.2 between a set value T.sub.C for the return fluid temperature T.sub.2 of a heat transfer fluid and the actually controlled return fluid temperature T.sub.2. In response to the instruction, the high-precision PID temperature controller (10) controls the heating power of a heater (17) for heating control through a constant-power thyristor phase controller (16). The heater (17) heats the heat transfer fluid and sends it to a machining apparatus (1) through a closed damping tank (21). The heat transfer fluid exchanges heat with the machining apparatus (1) and is then returned to a precooling means.

Abstract: A hydrostatic bearing apparatus comprises a base member having a static pressure guide surface to which a static pressure pocket is formed, a temperature detector for detecting a temperature of an operation oil in the static pressure pocket at an outlet portion thereof and generating a signal representing the detected outlet temperature of the operation oil, a temperature controller for controlling a temperature of the operation oil to be supplied in the static pressure pocket in response to the signal from the temperature detector, and a pressure controller for controlling a pressure in the static pressure pocket by controlling a flow rate of the operation oil supplied to the static pressure pocket. An operation oil source storing the operation oil to be supplied to the static pressure pocket is further disposed.

Abstract: A hydrostatic bearing apparatus comprises a base member having a static pressure guide surface to which a static pressure pocket is formed, a temperature detector for detecting a temperature of an operation oil in the static pressure pocket at an outlet portion thereof and generating a signal representing the detected outlet temperature of the operation oil, a temperature controller for controlling a temperature of the operation oil to be supplied in the static pressure pocket in response to the signal from the temperature detector, and a pressure controller for controlling a pressure in the static pressure pocket by controlling a flow rate of the operation oil supplied to the static pressure pocket. An operation oil source storing the operation oil to be supplied to the static pressure pocket is further disposed.