Apparatus and method for OFDM communication
View Patent ↗The OFDM reception apparatus according to the present invention comprising: FFT processor for performing a FFT processing on a reception signal; a plurality of demodulators capable of performing mutually different demodulation processes on the FFT-processed reception signal; and a selector for selecting, among the plurality of demodulators, a demodulator that should perform the demodulation process on the FFT-processed reception signal according to a factor that influences the quality of a demodulated signal and letting the selected demodulator perform the demodulation process.
1. A radio reception apparatus, comprising:
a demodulator that performs selectively (i) coherent detection of a received signal and (ii) delay detection of the received signal; and
a selector that selects one of said coherent detection and said delay detection to be applied to the received signal by said demodulator according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed.
2. A radio transmission apparatus, comprising:
a modulator that performs (i) a first modulation and (ii) a second modulation of a transmission signal to produce a first modulated signal and a second modulated signal, respectively, said first modulation corresponding to coherent detection and said second modulation corresponding to delay detection; and
a selector th at selects one of said first and second modulated signals for transmission by said radio transmission apparatus, wherein:
said selector selects between said first and second modulated signals according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed.
3. A radio transmission apparatus, comprising:
a modulator; and
a selector;
wherein said modulator performs selectively (i) a first modulation corresponding to coherent detection and (ii) a second modulation corresponding to delay detection, respectively, with respect to a signal to be output by said selector for transmission; and
wherein said selector selects between said first modulation and said second modulation with respect to said signal to be output by said selector for transmission, according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed.
4. A communication terminal apparatus, comprising the radio reception apparatus of claim 1 .
5. A communication terminal apparatus, comprising the radio transmission apparatus of claim 2 .
6. A communication terminal apparatus, comprising the radio transmission apparatus of claim 3 .
7. A communication terminal apparatus, comprising: a radio reception apparatus comprising a demodulator that performs selectively (i) coherent detection of a received signal and (ii) delay detection of a received signal; and a selector that selects one of said coherent detection and said delay detection to be applied to the received signal by said demodulator according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed; and
the radio transmission apparatus of claim 2 .
8. A communication terminal apparatus, comprising:
a radio reception apparatus comprising a demodulator that performs selectively (i) coherent detection of a received signal and (ii) delay detection of a received signal; and a selector that selects one of said coherent detection and said delay detection to be applied to the received signal by said demodulator according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed; and
the radio transmission apparatus of claim 3 .
9. A base station apparatus, comprising the radio reception apparatus of claim 1 .
10. A base station apparatus, comprising the radio transmission apparatus of claim 2 .
11. A base station apparatus, comprising the radio transmission apparatus of claim 3 .
12. A base station apparatus, comprising:
a radio reception apparatus comprising a demodulator that performs selectively (i) coherent detection of a received signal and (ii) delay detection of a received signal; and a selector that selects one of said coherent detection and said delay detection to be applied to the received signal by said demodulator according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed; and
the radio transmission apparatus of claim 2 .
13. A base station apparatus, comprising:
a radio reception apparatus comprising a demodulator that performs selectively (i) coherent detection of a received signal and (ii) delay detection of a received signal; and a selector that selects one of said coherent detection and said delay detection to be applied to the received signal by said demodulator according to: (a) a relationship between a communication speed of a packet and a channel variation speed, (b) the length of the packet, or (c) said channel variation speed; and
the radio transmission apparatus of claim 3 .
14. A radio reception method, comprising:
(a) performing selectively coherent detection and delay detection of a received signal; and
(b) selecting one of said coherent detection and delay detection to be applied to the received signal in step (a) according to: (i) a relationship between a communication speed of a packet and a channel variation speed, (ii) the length of the packet, or (iii) said channel variation speed.