TRANSMITTER, RECEIVER, COMMUNICATION SYSTEM, COMMUNICATION METHOD, AND INTEGRATED CIRCUIT

PROBLEM TO BE SOLVED: To properly estimate the amplitude and phase reception gain (complex gain) of a data signal at a terminal device while performing spatial multiplexing of De-Modulation Reference Signals (DMRS) and controlling the increase of overhead caused by DMRS insertion to the minimum in a Non-Linear Precoding Multi-User MIMO (NLP MU-MIMO) system.SOLUTION: A transmitter for transmitting a data signal at the same time and at the same frequency to a plurality of receivers comprises a transmission unit for transmitting a reference signal for demodulation destined to a first receiver and a reference signal for demodulation destined to a second receiver different from the first receiver at the same time and at the same frequency.