US 6,856,590 B2Granted

OFDM transmission device and OFDM transmission method

AssigneeSony Corporation

InventorsTakahiro Okada, Yoshikazu Miyato, Yasunari Ikeda, Tamotsu Ikeda

Life of this patent

Estimating the term…

Loading patent…

Abstract

The time required for switch the channel can be remarkably curtailed. When broadcasting signals through a plurality of information channels with an OFDM system, the plurality of information channels are multiplexed in the sense of frequency and collectively subjected to IFFT modulation for connected transmission instead of subjecting the plurality of information channels independently to OFDM modulation for transmission. With this arrangement, the efficiency of exploitation of frequencies is improved. According to the invention, the OFDM frames are synchronized for each information channel for the purpose of connected transmission. Then, the OFDM receiver can switch the information channel for signal reception, maintaining the frame synchronizing signals.

Claims10

Dependent claims

An OFDM transmission device comprising:

N encoders for generating an OFDM signal of a frequency domain containing a predetermined number of symbols and having a data structure formed on a symbol basis for transmission;
N frequency converters for converting carrier frequencies of the OFDM signals of the frequency domains output from the respective encoders;
a multiplexer for generating multiplexed data by multiplexing the N OFDM signals of the frequency domains frequency-converted respectively by said N frequency converters in a direction of frequency;
an inverse Fourier transform section for generating the OFDM signal of a base band by performing an operation of inverse Fourier transform on said multiplexed data on a symbol by symbol basis;
an orthogonal modulator for orthogonally modulating said OFDM signal of the base band;
and
a transmitter for converting the frequency of the orthogonally modulated OFDM signal into a signal of an RF band and transmitting said signal of the RF band;
each of said N encoders being adapted to synchronize the OFDM signals of frequency domains of the other encoders with a transmission frame to generate the OFDM signal of the frequency domain.

5 more elements

An OFDM transmission device comprising:

N encoders for generating an OFDM signal of a frequency domain to be transmitted through a predetermined information channel;
N frequency converters for converting carrier frequencies of the OFDM signals of the frequency domains output from each of said N encoders in accordance with the respective RF frequencies of said predetermined information channels;
a connecting multiplexer for generating connected and multiplexed data by multiplexing the N OFDM signals of the frequency domains frequency-converted respectively by said N frequency converters in the direction of frequency and connecting the multiplexed OFDM signals;
an inverse Fourier transform section for generating OFDM signals of base bands by performing an operation of inverse Fourier transform on said connected and multiplexed data on a symbol basis;
an orthogonal modulator for orthogonally modulating said OFDM signals of the base bands;
a transmitter for connected transmission of said OFDM signals of plurality of said information channels by frequency-converting the orthogonally modulated OFDM signals into a signal of an RF band;
and
each of said N encoders being adapted to include information on the connected transmission indicating whether the OFDM signal to be transmitted through the corresponding information channel is connected or unconnected to the OFDM signals to be transmitted through the other information channels in the OFDM signals before the connection.

5 more elements

An OFDM transmission method comprising the steps of:

generating an OFDM signal of a frequency domain to be transmitted through a predetermined information channel, including inf the OFDM signal the information on a connected transmission indicating whether the OFDM signal to be transmitted through the corresponding information channel is connected or unconnected to the OFDM signals to be transmitted through the other information channels;
converting the carrier frequencies of the OFDM signals of the frequency domains in accordance with the respective RF frequencies of said predetermined information channels and generating connected and multiplexed data by multiplexing the N OFDM signals of the frequency domains in the direction of frequency and connecting the multiplexed OFDM signals;
generating OFDM signals of base bands by performing an operation of inverse Fourier transform on said connected and multiplexed data on a symbol basis;
orthogonally modulating said OFDM signals of said base bands;
and
performing a connected transmission of said OFDM signals of plurality of said information channels by frequency-converting the orthogonally modulated OFDM signals into a signal of an RF band.

3 more elements

Dependencies are inferred from the claim text.