Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Time slice transmission methods transmit data in bursts, thus creating a delay until playback of a service can begin when changing the service and therefore preventing smooth zapping. To solve this problem, a first stream used for burst transmission of packet sets and a second stream for continuously transmitting packets at a speed determined according to the transmission rate required for a particular service are multiplexed and transmitted. The content is reproduced using the continuously transmitted second stream during zapping, and the first stream transmitted in bursts is reproduced after zapping ends.

Abstract: An OFDM reception device detects a time at which impulse noise occurs in a received OFDM signal, and specifies a start position candidate period that does not have intersymbol interference and is estimated to have a guard interval signal in a symbol. When setting a FFT window of an effective symbol length in a symbol duration of each symbol, if the impulse noise occurrence time is included in the symbol, the OFDM reception device determines a start position of the FFT window within a range of the start position candidate period so as to exclude the impulse noise occurrence time as much as possible.

Abstract: A mobile receiver performs oblique interpolation in such a direction that a symbol number increases by one and a carrier number decreases by three with respect to a position of each Scattered Pilot Signal to interpolate a first signal whose channel characteristics have not been obtained. The mobile receiver then performs, in a frequency axis direction, frequency axis interpolation to interpolate channel characteristics of a second signal whose channel characteristics have not been obtained, using the estimated channel characteristics and the interpolated channel characteristics.

Abstract: For a data group composed of pieces of data each indicating channel characteristics of a scattered pilot signal position whose phase is adjusted by dividing scattered pilot signals included in an OFDM signal by a scattered pilot signal at the time of transmission, a carrier extension circuit 341 inserts data having a same value as a value of data of a lower end into an outside of the lower end of a band, and inserts data having a same value as a value of data of an upper end into an outside of the upper end of the band. On the data group composed of 2N pieces of data including the data inserted by the carrier extension circuit 341, IFFT processing by an IFFT circuit 342, noise removal processing by a noise removal filter 343, and FFT processing by a FFT circuit 344 are performed. The data inserted by the carrier extension circuit 341 is removed from the data group outputted from the FFT circuit 344, and the data group after the data removal is used for interpolation in a symbol direction.

Abstract: For a data group composed of pieces of data each indicating channel characteristics of a scattered pilot signal position whose phase is adjusted by dividing scattered pilot signals included in an OFDM signal by a scattered pilot signal at the time of transmission, a carrier extension circuit 341 inserts data having a same value as a value of data of a lower end into an outside of the lower end of a band, and inserts data having a same value as a value of data of an upper end into an outside of the upper end of the band. On the data group composed of 2N pieces of data including the data inserted by the carrier extension circuit 341, IFFT processing by an IFFT circuit 342, noise removal processing by a noise removal filter 343, and FFT processing by a FFT circuit 344 are performed. The data inserted by the carrier extension circuit 341 is removed from the data group outputted from the FFT circuit 344, and the data group after the data removal is used for interpolation in a symbol direction.

Abstract: In the invention, zapping streams respectively relating to a plurality of normal service are set in one burst, and the burst is transmitted as a zapping burst. The zapping burst is transmitted in a cycle of one second or less. A PID dedicated to a zapping burst is added to the zapping burst. Association between the zapping burst and the normal service is designated by an IP source address, an IP destination address, or a port number. The transmission performed in this manner make it possible to perform a zapping process without considerably changing an IP encapsulator on a transmission side and an existing receiver.

Abstract: Disclosed is an OFDM signal receiving apparatus for diversity reception, with a plurality of antennas, of an OFDM signal containing Y sub-carriers, where 2X?1<Y<2X and X>1. The OFDM signal receiving apparatus includes a plurality of receiving systems, and a diversity processing unit connected to the receiving systems and fed with sequences of data on sub-carriers demodulated by the respective receiving systems. At least one of the receiving systems includes an FFT circuit for Fast Fourier transforming, in parallel, only a sequence of data on 2Z sub-carriers contained in the OFDM signal received with a corresponding antenna, where X>Z. The diversity processing unit performs a diversity process on sequences of data on sub-carriers, out of all the Y sub-carries, redundantly demodulated.

Abstract: An OFDM reception device detects a time at which impulse noise occurs in a received OFDM signal, and specifies a start position candidate period that does not have intersymbol interference and is estimated to have a guard interval signal in a symbol. When setting a FFT window of an effective symbol length in a symbol duration of each symbol, if the impulse noise occurrence time is included in the symbol, the OFDM reception device determines a start position of the FFT window within a range of the start position candidate period so as to exclude the impulse noise occurrence time as much as possible.

Abstract: To improve the reception performance of a mobile receiver for a digital broadcasting by OFDM method, the present invention focuses on the arrangement of the SP signals. The present invention performs oblique interpolation in such a direction that a symbol number increases by one and a carrier number decreases by three with respect to a position of each Scattered Pilot Signal to interpolate a first signal whose channel characteristics have not been obtained, and then performs, in a frequency axis direction, frequency axis interpolation to interpolate channel characteristics of a second signal whose channel characteristics have not been obtained, using the estimated channel characteristics and the interpolated channel characteristics.

Abstract: In communication transmitting a first stream (intermittent data portion) for burst transmission of packet sets and a second stream (continuous data portion) for transmitting packets at a speed determined by the transmission rate required for the service, the second stream related to the selected service is received and reproduced for the selected service when a service is selected until intermittent data transmitted in the first stream can be received, and reception and playback of the first stream begins when transmission of the intermittent data for the selected service in the first stream begins.

Abstract: 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.

Abstract: Although the capacity of a packet is reduced, a parity code generated by a shortened error correction code of RS (255,191) is inserted into a private data field of an adaptation field of a TS packet. In the adaptation field, as positions where the parity codes are inserted, two positions can be used. The first position is a “stuffing byte” field the length of which is indirectly known on the basis of an adaptation field length field. The second position is a “transport private data” field the length of which can be directly described by a transport private data length field.

Abstract: Disclosed is an OFDM signal receiving apparatus for diversity reception, with a plurality of antennas, of an OFDM signal containing Y sub-carriers, where 2X?1<Y<2X and X>1. The OFDM signal receiving apparatus includes a plurality of receiving systems, and a diversity processing unit connected to the receiving systems and fed with sequences of data on sub-carriers demodulated by the respective receiving systems. At least one of the receiving systems includes an FFT circuit for Fast Fourier transforming, in parallel, only a sequence of data on 2Z sub-carriers contained in the OFDM signal received with a corresponding antenna, where X>Z. The diversity processing unit performs a diversity process on sequences of data on sub-carriers, out of all the Y sub-carries, redundantly demodulated.

Abstract: Time slice transmission methods transmit data in bursts, thus creating a delay until playback of a service can begin when changing the service and therefore preventing smooth zapping. To solve this problem, a first stream used for burst transmission of packet sets and a second stream for continuously transmitting packets at a speed determined according to the transmission rate required for a particular service are multiplexed and transmitted. The content is reproduced using the continuously transmitted second stream during zapping, and the first stream transmitted in bursts is reproduced after zapping ends.

Abstract: A synchronous signal position detection unit detects symbol synchronous signals according to OFDM from the signals received by the respective antennas. A delay measurement unit measures a relative delay between the symbol synchronous signals for each antenna series and makes a notice to a memory unit via a delay amount notification unit. A diversity operation implementation unit temporally aligns the carrier data positions of the OFDM symbols for each antenna series so as to implement a space diversity operation.

Abstract: In a diversity receiver comprising an AGC section for controlling the gain of a tuner, an equalizer equalizes an outputted signal from a fast Fourier transformer. A reliability calculator calculates the reliability value of each of carriers by an equalized pilot signal obtained from the equalizer. A reliability value corrector corrects the reliability value by outputted information from the AGC section. A carrier selecting/combining section performs one of selecting and weighting combining for the carrier in a branch in accordance with the corrected reliability value. When a Viterbi decoder is provided, the Viterbi decoder weights an output from the carrier selecting/combining section with a new reliability value to perform maximum likelihood decoding. It is possible to prevent a reliability value which does not reflect an actually received power from being calculated as a result of increasing a power by an AGC in spatial diversity for every OFDM or FDM demodulated carrier.