Device and method for receiving digital signal transmitted using OFDM method
A receiver that receives a digital signal transmitted on the basis of an orthogonal frequency division multiplexing (OFDM) method. This receiver comprises a demodulation unit for demodulating the digital signal, a demapping unit for demapping demodulated data output from the demodulation unit, a frequency deinterleave unit for executing a frequency deinterleaving process on data output from the demapping unit, a delay unit for delaying control information superposed on the digital signal by a prescribed time period, and a time deinterleave unit for executing, on the basis of the interleave length specified by the control information delayed by the delay unit, a time deinterleaving process on data on which the frequency deinterleaving process has been executed.
1. A receiver that receives a digital signal transmitted on the basis of an orthogonal frequency division multiplexing (OFDM) method, comprising:
a demodulation unit which demodulates the digital signal;
a demapping unit which demaps demodulated data output from the demodulation unit;
a frequency deinterleave unit which executes a frequency deinterleaving process on data output from the demapping unit;
a delay unit which delays control information superposed on the digital signal by a prescribed time period; and
a time deinterleave unit which executes, on the basis of the interleave length specified by the control information delayed by the delay unit, a time deinterleaving process on data on which the frequency deinterleaving process has been executed.
2. The receiver according to claim 1 , wherein:
a soft decision is made with the number of bits determined on the basis of the control information in the demapping process.
3. The receiver according to claim 2 , wherein:
the number of bits is determined on the basis of the interleave length.
4. The receiver according to claim 2 , wherein:
the number of bits is determined on the basis of a modulation method of a subcarrier specified by the control information.
5. The receiver according to claim 2 , wherein:
the number of bits is determined in accordance with a redundant amount of memory that is obtained by subtracting, from memory capacity provided to the time deinterleave unit in advance, the amount of memory that is used for the time deinterleaving process.
6. A method of receiving a digital signal transmitted on the basis of an orthogonal frequency division multiplexing (OFDM) method, comprising:
demodulating the digital signal;
demapping demodulated data obtained by the demodulation;
executing a frequency deinterleaving process on the demapped data;
delaying control information superposed on the digital signal by a prescribed time period; and
executing, on the basis of the interleave length specified by the delayed control information, a time deinterleaving process on data on which the frequency deinterleaving process has been executed.
7. The method of receiving a digital signal according to claim 6 , wherein:
a soft decision is made with the number of bits determined on the basis of the control information in the demapping process.
8. The method of receiving a digital signal according to claim 7 , wherein:
the number of bits is determined on the basis of the interleave length.
9. The method of receiving a digital signal according to claim 7 , wherein:
the number of bits is determined on the basis of a modulation method of a subcarrier specified by the control information.
10. The method of receiving a digital signal according to claim 7 , wherein:
the number of bits is determined in accordance with a redundant amount of memory that is obtained by subtracting, from memory capacity provided to the time deinterleaving process in advance, the amount of memory that is used for the time deinterleaving process.