1. A laser processing device for converging laser light at an object to be processed having a silicon part containing silicon mounted on a glass part containing glass with a resin part interposed therebetween so as to form a modified region within the object along a line to cut, the laser processing device comprising:
a laser light source emitting the laser light;
a spatial light modulator modulating the laser light emitted from the laser light source; and
a converging optical system converging the laser light modulated by the spatial light modulator at the object;
wherein, when forming the modified region in the glass part, the spatial light modulator displays an axicon lens pattern as a modulation pattern so as to form converging points at a plurality of positions juxtaposed close to each other along a laser light irradiation direction.
2. A laser processing device according to claim 1, wherein the laser processing device forms a plurality of modified spots within the object along the line and lets a plurality of the modified regions form the modified region;
wherein, when forming the modified region in the glass part, the spatial light modulator forms modified dots respectively at the plurality of positions juxtaposed close to each other along the laser light irradiation direction; and
wherein a plurality of the modified dots constitute the modified spot elongated in the laser light irradiation direction.
3. A laser processing device according to claim 1, wherein, in a display part of the spatial light modulator, the axicon lens pattern has a circular region located at a center of the laser light incident thereon and a plurality of circular ring regions demarcated about the center region concentrically with the circular region; and
wherein each of the circular region and the plurality of circular ring regions is set such as to increase brightness gradually from radially outer side to inner side.
4. A laser processing device according to claim 1, further comprising a controller controlling the laser light;
wherein the controller controls a position of a converging point of the laser light so as to form the modified region within the glass part, only in a part on the silicon part side from a center of the glass part, in the laser light irradiation direction.
5. A laser processing device according to claim 1, wherein, when forming the modified region in the resin part, the spatial light modulator displays an axicon lens pattern as a modulation pattern, so as to converge the laser light such that converging points are formed respectively at a plurality of positions juxtaposed close to each other along the laser light irradiation direction.
6. A laser processing method for converging laser light at an object to be processed having a silicon part containing silicon mounted on a glass part containing glass with a resin part interposed therebetween so as to form a modified region within the object along a line to cut, the method comprising the step of:
forming the modified region in the glass part by modulating the laser light emitted from a laser light source with a spatial light modulator and converging the laser light modulated by the spatial light modulator within the glass part;
wherein the step of forming the modified region in the glass part causes the spatial light modulator to display an axicon lens pattern as a modulation pattern so as to form converging points within the glass part at a plurality of positions juxtaposed close to each other along a laser light irradiation direction.
7. A laser processing device according to claim 2, wherein, in a display part of the spatial light modulator, the axicon lens pattern has a circular region located at a center of the laser light incident thereon and a plurality of circular ring regions demarcated about the center region concentrically with the circular region; and
wherein each of the circular region and the plurality of circular ring regions is set such as to increase brightness gradually from radially outer side to inner side.
8. A laser processing device according to claim 2, further comprising a controller controlling the laser light;
wherein the controller controls a position of a converging point of the laser light so as to form the modified region within the glass part, only in a part on the silicon part side from a center of the glass part, in the laser light irradiation direction.
9. A laser processing device according to claim 3, further comprising a controller controlling the laser light;
wherein the controller controls a position of a converging point of the laser light so as to form the modified region within the glass part, only in a part on the silicon part side from a center of the glass part, in the laser light irradiation direction.
10. A laser processing device according to claim 2, wherein, when forming the modified region in the resin part, the spatial light modulator displays an axicon lens pattern as a modulation pattern, so as to converge the laser light such that converging points are formed respectively at a plurality of positions juxtaposed close to each other along the laser light irradiation direction.
11. A laser processing device according to claim 3, wherein, when forming the modified region in the resin part, the spatial light modulator displays an axicon lens pattern as a modulation pattern, so as to converge the laser light such that converging points are formed respectively at a plurality of positions juxtaposed close to each other along the laser light irradiation direction.
12. A laser processing device according to claim 4, wherein, when forming the modified region in the resin part, the spatial light modulator displays an axicon lens pattern as a modulation pattern, so as to converge the laser light such that converging points are formed respectively at a plurality of positions juxtaposed close to each other along the laser light irradiation direction.
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 pilot designing method in an uplink orthogonal frequency division multiple access (OFDMA) system where communications are carried out in a frame divided into time-frequency lattices, each time-frequency lattice including a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods, comprising the steps of:
dividing the frame into a plurality of blocks;
assigning the blocks to the terminals; and
sharing a predetermined allocated pilot time-frequency lattice between adjacent terminals.
2. The pilot designing method of claim 1, wherein the step of sharing the time-frequency lattice comprises inserting a pilot signal of a predetermined terminal and a pilot signal of an adjacent terminal in at least one pilot time-frequency lattice of the pilot symbol period allocated to a predetermined terminal.
3. The pilot designing method of claim 2, wherein the pilot signal of the predetermined terminal is orthogonal to the pilot signal of the adjacent terminal.
4. The pilot designing method of claim 1, wherein the step of sharing the time-frequency lattice comprises inserting only the pilot signal of an adjacent terminal in one of at least two pilot time-frequency lattices of the pilot symbol periods allocated to a predetermined terminal.
5. A data transmitting method in an uplink orthogonal frequency division multiple access (OFDMA) system where, for communication, a frame having time-frequency lattices is divided into a plurality of blocks, the blocks being allocated to the terminals, each time-frequency lattice including a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods, comprising the steps of:
arranging data signals and pilot signals of each terminal in the data symbol periods and the pilot symbol periods, respectively, of a block allocated to the terminal;
generating a transmission frame by inserting pilot signals of the terminal in predetermined pilot time-frequency lattices of an adjacent block allocated to a different terminal; and
transmitting the transmission frame.
6. A data transmitting method in an uplink orthogonal frequency division multiple access (OFDMA) communication system where a frame having time-frequency lattices is divided into a plurality of blocks, the blocks being allocated to the terminals, each time-frequency lattice including a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods, comprising the steps of:
arranging data signals and pilot signals of each terminal in the data symbol periods and the pilot symbol periods, respectively of a block allocated to the terminal;
emptying one of at least two time-frequency lattices of the pilot symbol period of the terminal, for filling a pilot signal of a different terminal in the empty time-frequency lattice;
generating a transmission frame by inserting a pilot signal of the terminal in an empty pilot time-frequency lattice among at least two pilot time-frequency lattices of an adjacent block allocated to the different terminal; and
transmitting the transmission frame.
7. A channel estimation method in an uplink orthogonal frequency division multiple access (OFDMA) communication system where a frame having time-frequency lattices is divided into a plurality of blocks, the blocks being allocated to the terminals, each time-frequency lattice including a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods, comprising the steps of:
receiving a frame with time-frequency lattices shared between adjacent blocks; and
estimating a channel of each of the terminals using a pilot signal included in a time-frequency lattice shared with an adjacent block allocated to a different terminal.
8. A channel estimation method in an uplink orthogonal frequency division multiple access (OFDMA) communication system where a frame having time-frequency lattices is divided into a plurality of blocks, the blocks being allocated to the terminals, each time-frequency lattice including a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods, comprising the steps of:
receiving a frame with time-frequency lattices which are exchanged between adjacent blocks; and
estimating a channel of each of the terminals using a pilot signal included in a time-frequency lattice exchanged from an adjacent block allocated to a different terminal.
9. A pilot designing method in an uplink orthogonal frequency division multiple access (OFDMA) system where communications are carried out in a frame divided into time-frequency lattices, each time-frequency lattice being identified by frequency-axis subcarrier indexes and time-axis symbol period indexes and including a plurality of intermittently arranged pilot subcarriers, comprising the steps of:
dividing the frame into transport blocks of a predetermined size and allocating the transport blocks to terminals; and
sharing pilot subcarriers of adjacent transport blocks allocated to different terminals in at least one symbol period.
10. The pilot designing method of claim 9, wherein the pilot subcarriers are shifted to other subcarrier indexes at predetermined symbol period intervals.
11. The pilot designing method of claim 10, wherein a transport block allocated to each terminal is shared by at least two antennas of the terminal.
12. The pilot designing method of claim 11, wherein the antennas map orthogonal pilot signals to pilot subcarriers in the transport block.
13. The pilot designing method of claim 10, wherein a pilot subcarrier is shared by the different terminals for four symbol periods.
14. The pilot designing method of claim 13, wherein a transport block allocated to each terminal is shared by at least two antennas of the terminal.
15. The pilot designing method of claim 14, wherein the pilot subcarrier is selectively allocated to the two antennas of the terminal for two successive symbol periods.
16. The pilot designing method of claim 15, wherein a pilot signal is mapped to pilot subcarriers having different indexes in the transport block for different symbol periods.
17. The pilot designing method of claim 14, wherein the pilot subcarrier is allocated to the two antennas of the terminal for the same two successive symbol periods.
18. The pilot designing method of claim 17, wherein a pilot signal is mapped to pilot subcarriers having different indexes in the transport block for different symbol periods.
19. The pilot designing method of claim 18, wherein the pilot signals mapped to the two antennas of the terminal are orthogonal to each other.
20. The pilot designing method of claim 13, wherein the pilot subcarrier is selectively allocated to at least two antennas of the terminal for a different symbol period.
21. The pilot designing method of claim 20, wherein a pilot signal is mapped to pilot subcarriers having different indexes in the transport block for different symbol periods.
22. A pilot designing method in an uplink orthogonal frequency division multiple access (OFDMA) system where communications are carried out in a frame divided into time-frequency lattices, each time-frequency lattice being identified by frequency-axis subcarrier indexes and time-axis symbol period indexes and including a plurality of intermittently arranged pilot symbol periods, comprising the steps of:
dividing the frame into transport blocks of a predetermined size and allocating the transport blocks to terminals; and
sharing pilot symbol periods of adjacent transport blocks allocated to different terminals in at least one subcarrier.
23. The pilot designing method of claim 22, wherein a transport block allocated to each terminal is shared by at least two antennas of the terminal.
24. The pilot designing method of claim 23, wherein the antennas map orthogonal pilot signals to pilot symbol periods in the transport block.