1. A transmission device comprising:
a waveform generator to generate a transmission signal by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel; and
a transmitter to transmit the transmission signal generated by the waveform generator.
2. The transmission device according to claim 1, further comprising:
a modulation processor, provided before the waveform generator, to perform \u03c02 shift BPSK modulation on the transmission data.
3. A transmission device comprising:
a spreader to spread transmission data in a time domain by using only a long code spreading sequence, without using a short code spreading sequence;
a waveform generator to generate, by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel, a transmission waveform from the data spread by the spreader; and
a transmitter to transmit the transmission waveform generated by the waveform generator.
4. A transmission device comprising:
an encoder to encode transmission data, the encoder being capable of switching between a differential encoding and a non-differential encoding that does not include a phase reference signal;
a waveform generator to generate, by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel, a transmission waveform from the data encoded by the encoder; and
a transmitter to transmit the transmission waveform generated by the waveform generator.
5. A transmission device comprising:
a Reed-Solomon encoder to Reed-Solomon encode transmission data;
a convolutional encoder to convolution ally encode the transmission data;
a spreader to spread the transmission data in a time domain; and
a rate controller to control transmission rate of the transmission data by controlling ON-OFF of encoding by the Reed-Solomon encoder, ON-OFF of encoding by the convolutional encoder, or spreading factor of the spreader.
6. A transmission device comprising:
a first convolutional encoder to convolutionally encode transmission data;
a second convolutional encoder that is connected in parallel with the first convolutional encoder;
a selector to alternately input the transmission data to the first convolutional encoder and the second convolutional encoder; and
a controller to turn off one of the first convolutional encoder and the second convolutional encoder according to a transmission rate of the transmission data.
7. A communication system comprising:
a transmission device having
a waveform generator to generate a transmission signal by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel, and
a transmitter to transmit the transmission signal generated by the waveform generator; and
a reception device that is connected to the transmission device via the wireless channel in a communicable manner and that includes the analog domain extending from the wireless channel to an A-D converter for a received signal.
8. A transmission method comprising the steps of:
generating a transmission signal by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel; and
transmitting the generated transmission signal.
9. A program causing a computer to function as:
a unit to generate a transmission signal by using a transfer function that is in a relation of a matched filter with a transfer function in an analog domain of a transmission side and a reception side connected through a wireless channel; and
a unit to transmit the generated transmission signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of growth of a nitride thin film on a sapphire substrate comprising steps of irradiating an electron beam on the sapphire substrate treated by high temperature hydrogen in advance, and depositing a nitride thin film by the metal-organic chemical vapor deposition method on the substrate treated by the electron beam, thereby forming a pattern of the nitride thin film.
2. A method of growth of a nitride thin film on a sapphire substrate comprising steps of:
(a) irradiating an electron beam with a fine width on the sapphire substrate treated by high temperature hydrogen in advance;
(b) depositing a nitride thin film by the metal-organic chemical vapor deposition method on the substrate treated by the electron beam; and
(c) etching the nitride thin film in an alkaline solution, thereby forming a fine pattern of the nitride thin film corresponding to the fine width of the irradiating electron beam.
3. The method of growth of a nitride thin film on a sapphire substrate according to claim 1 or 2, wherein the nitride thin film is a GaN thin film.
4. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein the electron beam is an electron beam generated from the Reflection High Energy Electron Diffraction (RHEED).
5. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein the irradiation by electron beam from the Reflection High Energy Electron Diffraction (RHEED) is performed at room temperature.
6. The method of growth of a nitride thin film on a sapphire substrate according to claim 5, wherein the irradiation is performed for one or more minutes.
7. The method of growth of a nitride thin film on a sapphire substrate according to 1, 2, or 3, wherein the electron beam is an electron beam of the electron beam lithography.
8. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein the high temperature hydrogen treatment is a hydrogen treatment at or above 1000\xb0 C. for about 20 minutes.
9. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein the nitride thin film is grown while a nitride thin film having a different polar face is simultaneously grown.
10. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein an electrode is formed on the substrate to apply an electric field to the nitride thin film whose polar structure and its position are controlled.
11. The method of growth of a nitride thin film on a sapphire substrate according to claim 1, 2, or 3, wherein the fine pattern of the nitride thin film is stripes having intervals of several tens of \u03bcm between each stripe.
12. A device using a nitride thin film, wherein the device is realized by using the method of growth of the nitride thin film on a sapphire substrate in any one of the above claims 1 to 11.