A method and device to modulate an FBMC/OQAM signal, the device comprising at least one QAM mapper mapping a binary stream into complex symbols, a first and a second transmission chain. Each chain comprises: a precoder transposing respective sets of symbols into frequency domain real/imaginary samples, a phase rotator applying a phase quadrature keying to said samples, an FBMC modulator to modulate the output of the phase rotator into an FBMC symbol. The device further comprises an adder of the output of the first transmission chain with a delayed output of the second transmission chain, and is configured to insert guard interval sequences into the binary stream or into the symbols processed by the precoders. A corresponding radio communication equipment, computer program and readable medium is provided.