Wireless transmission device, wireless reception device, and symbol arranging method
A wireless transmission device enabled to improve an error rate performance at a receiver, by acquiring at least one of frequency diversity effect and a time diversity effect while keeping the interference resistance which is acquired by diffusion. In this transmission device, a modulation unit ( 101 ) modulates data to create a modulation symbol having in-phase components and quadrature components. An IQ individual spreading unit ( 102 ) arranges the diffusion chips, which are obtained by spreading the modulation symbol, of the in-phase components and the quadrature components, in areas extending in diffusion domains set individually for the in-phase components and the quadrature components. An IQ combining unit ( 103 ) combines the arranged spreading chips of the in-phase components and the quadrature components.
1. A wireless transmission apparatus comprising:
a modulation section that modulates data to generate a modulation symbol comprised of an in-phase component and a quadrature component;
an arrangement section that arranges a spreading chip of the in-phase component and a spreading chip of the quadrature component obtained by spreading the modulation symbol in regions extending in spreading domains set for the in-phase component and the quadrature component individually; and
a combining section that combines the arranged spreading chip of the in-phase component and the arranged spreading chip of the quadrature component wherein:
the arrangement section comprises a spreading domain setting section that individually and variably sets the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component; the spreading domain setting section sets the spreading domain of the spreading chip of the in-phase component to one of a time domain and a frequency domain, sets the spreading domain of the spreading chip of the quadrature component to one of the time domain and the frequency domain, and changes the set domain of the time domain or the frequency domain in accordance with a transmission data parameter.
2. The wireless transmission apparatus of claim 1 , wherein the spreading domain setting section sets the spreading domain of the spreading chip of the in-phase component to one of a time domain and a frequency, sets the spreading domain of the spreading chip of the quadrature component to one of the time domain and the frequency domain, and changes the set domain of the time domain or the frequency domain in accordance with information indicating a propagation path condition.
3. The wireless transmission apparatus of claim 1 , wherein the spreading domain setting section selects one of a first setting that allows the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component to be in a same domain, and a second setting that allows the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component to be in different domains.
4. The wireless transmission apparatus of claim 1 , wherein the spreading domain setting section sets the spreading domain using a threshold value that changes only one of the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component.
5. The wireless transmission apparatus of claim 1 , wherein the spreading domain setting section changes one of the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component in accordance with a number of retransmissions.
6. The wireless transmission apparatus of claim 5 , wherein the spreading domain setting section exchanges the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component at a time of retransmission.
7. The wireless transmission apparatus of claim 1 , wherein the arrangement section arranges the spreading chip of the in-phase component in a region extending in one of a time domain and a frequency domain, and arranges the spreading chip of the quadrature component in a region extending in another domain of the time domain and the frequency domain.
8. The wireless transmission apparatus of claim 1 , wherein the arrangement section arranges the spreading chip of the in-phase component and the spreading chip of the quadrature component at a first region and a second region respectively, the first region and the second region both extending in the time domain and having different positions on the frequency domain.
9. The wireless transmission apparatus of claim 1 , wherein the arrangement section arranges the spreading chip of the in-phase component and the spreading chip of the quadrature component at a first region and a second region respectively, the first region and the second region both extending in the frequency domain and having different positions on the time domain.
10. The wireless transmission apparatus of claim 1 , wherein the arrangement section arranges the spreading chip of the in-phase component and the spreading chip of the quadrature component, spaced apart from each other.
11. The wireless transmission apparatus of claim 1 , wherein the arrangement section comprises a rearrangement section that rearranges one of the spreading chip of the in-phase component and the spreading chip of the quadrature component in a region in which a mutual separation distance is increased.
12. The wireless transmission apparatus of claim 1 , wherein the arrangement section comprises a randomizing section that randomizes arrangement of one of the spreading chip of the in-phase component and the spreading chip of the quadrature component.
13. A wireless transmission apparatus comprising:
a modulation section that modulates data to generate a modulation symbol comprised of an in-phase component and a quadrature component;
an arrangement section that arranges a spreading chip of the in-phase component and a spreading chip of the quadrature component obtained by spreading the modulation symbol in regions extending in spreading domains set for the in-phase component and the quadrature component individually; and
a combining section that combines the arranged spreading chip of the in-phase component and the arranged spreading chip of the quadrature component, wherein:
the arrangement section comprises:
a spreading factor setting section that sets a spreading factor for the in-phase component and a spreading factor for the quadrature component individually;
a separating section that separates the modulation symbol into the in-phase component and the quadrature component;
a conversion section that converts part of one of the separated in-phase component and the separated quadrature component into another component; and
a spreading section that spreads the in-phase component and the quadrature component, part of one of the components being converted into the another component, by corresponding spreading factors.
14. A symbol arrangement method of arranging a modulation symbol comprised of an in-phase component and quadrature component, the symbol arrangement method comprising:
arranging a spreading chip of an in-phase component and a spreading chip of a quadrature component obtained by spreading the modulation symbol in regions extending in spreading domains set for the in-phase component and the quadrature component individually;
setting the spreading domain of the spreading chip of the in-phase component to one of a time domain and a frequency domain, setting the spreading domain of the spreading chip of the quadrature component to one of the time domain and the frequency domain, and changing the set domain of the time domain or the frequency domain in accordance with a transmission data parameter; and
individually and variably setting the spreading domain of the spreading chip of the in-phase component and the spreading domain of the spreading chip of the quadrature component.
15. A symbol arrangement method comprising: modulating data to generate a modulation symbol comprised of an in-phase component and a quadrature component;
separating the modulation symbol into the in-phase component and the quadrature component;
converting part of one of the separated in-phase component and the separated quadrature component into another component; and
setting a spreading factor for the in-phase component and a spreading factor for the quadrature component individually;
spreading the in-phase component and the quadrature component, part of one of the components being converted into the another component, by corresponding spreading factors;
arranging a spreading chip of the in-phase component and a spreading chip of the quadrature component obtained by spreading the modulation symbol in regions extending in spreading domains set for the in-phase component and the quadrature component individually;
combining the arranged spreading chip of the in-phase component and the arranged spreading chip of the quadrature component.