Transmission device and transmission method
A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i×Δλ to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. Δλ satisfies π/2 radians<Δλ<π radians or π radians<Δλ<3π/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.
1. A transmission device, comprising:
a weighting synthesizer that generates a first precoded signal and a second precoded signal by performing a precoding process on a first baseband signal and a second baseband signal, respectively;
a first pilot inserter that inserts a pilot signal into the first precoded signal;
a first phase changer that applies a phase change of i×Δλ, to the second precoded signal, depending on a communications scheme, where i is a symbol number and an integer that is greater than or equal to 0;
a second pilot inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and
a second phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal, depending on the communications scheme,
wherein Δκ is π−π/m radians, where m is a natural number, and
each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.
2. A transmission method, comprising:
generating a first precoded signal and a second precoded signal by performing a precoding process on a first baseband signal and a second baseband signal, respectively;
inserting a pilot signal into the first precoded signal;
applying, as a first phase change process, a phase change of i×Δλ to the second precoded signal, depending on a communications scheme, where i is a symbol number and an integer that is greater than or equal to 0;
inserting a pilot signal into the second precoded signal applied with the phase change; and
applying, as a second phase change process, a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal, depending on the communications scheme,
wherein Δλ is π−π/m radians, where m is a natural number, and
each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.