Multicarrier transmitter and multicarrier receiver

Abstract

A multicarrier transmitter and a multicarrier receiver both enabling improvement of the reception characteristic of hierarchical modulation multiplex communication. A base station (100) transmits a multicarrier signal which is a superposition of a modulated signal addressed to a far user and a modulated signal addressed to a near user and modulated with a modulation multivalued number different from that of the modulated signal addressed to the far user. The base station (100) comprises a DFT section (120), an S/P section (125), and a combining section (145). The DFT section (120) separates the modulated signal addressed to the far user into signals in frequency ranges for each symbol. The S/P section (125) serial/parallel-transforms the modulated signal addressed to the near user to generate N1 parallel signals. The combining section (145) combines the N1 frequency components generated by the DFT section (120) and the N1 parallel signals. Since the far user receiver can change the modulated signal addressed to the near user into white noise by IDFT, the far user receiver can demodulate the modulated signal addressed to the far user with high accuracy. The near user receiver can acquire the signal addressed thereto with high accuracy by subtracting the modulated signal addressed to the far user, which is an interference signal, from the received signal.

Dependencies are inferred from the claim text.