摘要:
A synchronization section 101 specifies a position of a guard interval correlation's center of gravity based on a guard interval correlation value, and calculates a carrier-direction shift amount Fshift. An equalization section 102 shifts the passband of a carrier interpolation filter of a carrier interpolation section 111 by the carrier-direction shift amount Fshift calculated by the synchronization section 101. This shift processing causes the delay profile to be kept in the center of the passband of the carrier interpolation filter, for any FFT window position. This enables transmission path estimation without limiting a range of an FFT window position even if the passband of the carrier interpolation filter is narrower than a guard interval of an OFDM signal.
摘要:
A synchronization section specifies a position of a guard interval correlation's center of gravity based on a guard interval correlation value, and calculates a carrier-direction shift amount Fshift. An equalization section shifts the passband of a carrier interpolation filter of a carrier interpolation section by the carrier-direction shift amount Fshift calculated by the synchronization section. This shift processing causes the delay profile to be kept in the center of the passband of the carrier interpolation filter, for any FFT window position. This enables transmission path estimation without limiting a range of an FFT window position even if the passband of the carrier interpolation filter is narrower than a guard interval of an OFDM signal.
摘要:
A transmission method of a digital broadcast, which is compatible with a DVB-T terrestrial digital broadcast system in Europe, saves a battery in a mobile terminal. Superframes in DVB-T are divided into units each including plural symbols so that an integer number of TS packets can be carried in each slot. At least one slot is used to transmit one service. Energy dispersion, Reed-Solomon coding, byte interleaving, convolutional coding, and time interleaving are applied to each service. When services for mobile terminal reception and services for fixed terminals are transmitted as the provided services, null packets may be transmitted before and after the slot carrying the mobile receiver service so that the fixed reception service and the mobile reception services are not mixed.
摘要:
A channel characteristic calculation unit 23 estimates channel characteristics based on SP signals included in received signals, and a symbol interpolation filter 24 frequency-shifts frequency transfer characteristics and filters output signals of the channel characteristic calculation unit 23. A filter control unit 27 estimates channel characteristics based on CP signals included in the received signals and observes the estimated channel characteristics to determine a shift amount by which the symbol interpolation filter 24 frequency-shifts the frequency transfer characteristics. The symbol interpolation filter 24 frequency-shifts the frequency transfer characteristics based on the shift amount determined by the filter control unit 27.
摘要:
There is provided a signal demodulating device, including: a time frequency converting unit (6) for converting a frequency division multiplexing signal on a time axis into a signal on a frequency axis to output a data carrier, a pilot carrier, and a transmission control carrier; an equalizer (7) for equalizing the data carrier and the transmission control carrier according to a characteristic value of a transmission line obtained from the pilot carrier to output an equalized data carrier and an equalized transmission control carrier; a first decoding unit (9) for decoding the equalized transmission control carrier; and a first correcting unit (10) for performing first error-correction on an output of said first decoding unit (9) to output first control information and a first decoding flag that indicates a status of the first error-correction.
摘要:
Channel characteristic calculation unit 23 estimates channel characteristics based on SP signals included in received signals, symbol interpolation filter 24 is able to frequency-shift frequency transfer characteristics and filters output signals of the channel characteristic calculation unit 23. Filter control unit 27 estimates channel characteristics based on CP signals included in the received signals and observes the estimated channel characteristics to determine a shift amount by which the symbol interpolation filter 24 frequency-shifts the frequency transfer characteristics. The symbol interpolation filter 24 frequency-shifts the frequency transfer characteristics based on the shift amount determined by the filter control unit 27.
摘要:
SP signals to be transmitted from a first transmitting antenna are arranged in the same pattern as SP signals to be transmitted from a second transmitting antenna. The SP signals to be transmitted from the second transmitting antenna in one symbol are generated, such that the polarity of the SP signals are alternately inverted and non-inverted with respect to the SP signals to be transmitted from the first transmitting antenna in the same symbol. Thus, in the direction that the symbol number is incremented by 1 and the carrier number is incremented by 3, the polarity of SP signals transmitted from the second transmitting antenna are all inverted or non-inverted with respect to the polarity of corresponding SP signals transmitted from the first transmitting antenna.
摘要:
A transmitter modulates for each symbol period a plurality of carriers that include a carrier group that is consisted of a plurality of prescribed carriers, and repeatedly transmits control information in cycles by using the carrier group. The transmitter transmits multiple-bit binary data of the control information in each symbol period, thereby transmitting the control information once in each of the cycles that includes at least one symbol period. The transmitter controls the transmission unit to switch, within the carrier group, for each of the cycles, carriers of bits of the control information, according to a prescribed rule.
摘要:
SP signals to be transmitted from a first transmitting antenna 11 are arranged in the same pattern as SP signals to be transmitted from a second transmitting antenna 12. The SP signals to be transmitted from the second transmitting antenna 12 in one symbol are generated, such that the polarity of the SP signals are alternately inverted and non-inverted with respect to the SP signals to be transmitted from the first transmitting antenna 11 in the same symbol. Thus, in the direction that the symbol number is incremented by 1 and the carrier number is incremented by 3, the polarity of SP signals transmitted from the second transmitting antenna 12 are all inverted or non-inverted with respect to the polarity of corresponding SP signals transmitted from the first transmitting antenna 11.
摘要:
A transmission method of a digital broadcast which is compatible with the DVB-T terrestrial digital broadcast system in Europe and saves a battery in a mobile terminal is provided. Superframes in DVB-T are divided into units each including plural symbols so that an integer number of TS packets can be carried in each slot. At least one slot is used to transmit one service. Energy dispersion, Reed-Solomon coding, byte interleaving, convolutional coding, and time interleaving are applied to each service. When services for mobile terminal reception and services for fixed terminals are transmitted as the provided services, null packets may be transmitted before and after the slot carrying the mobile receiver service so that the fixed reception service and the mobile reception services are not mixed. If the fixed terminal handles TS packets of the mobile reception service as error packets, it could have no problem in reception.