A high speed digital bit generator for an optical frontal interface comprising: a set of input ports to receive baseband samples of a signal to be transmitted on a set of disjoint frequency bands, each input port receives a sequence of baseband samples for transmission on a corresponding RF frequency band; a set of filter banks, comprising one filter bank for each input port, wherein each filter bank includes a plurality of digital polyphase interpolation filters (210, 220, 230) to sample a shifted phase of the corresponding sequence of baseband samples and to interpolate the sampled phases to produce a plurality of sequences of interpolated baseband phased samples with the shifted phase; a set of oscillators banks comprising one oscillator bank for each filter bank, wherein each oscillator bank includes a plurality of polyphase Digital Direct Synthesizer, DDS, corresponding to the plurality of digital polyphase interpolation filters (210, 220, 230) to generate a plurality of sequences of samples of digital waveform comprising one sequence of samples of digital waveform for each of the interpolated baseband phased samples, wherein the sequence of samples of digital waveform is phase synchronized with the corresponding interpolated baseband phased samples, wherein an effective frequency of the digital waveform equals a RF sampling rate divided by the number of the plurality of interpolated baseband phased samples; a set of mixer banks comprising one mixer bank for each filter bank, wherein each mixer bank includes a plurality of parallel digital mixers to mix corresponding sequences of samples of digital waveform and interpolated baseband phased samples to up convert each sequence of interpolated baseband phased samples to the effective frequency; a parallel digital combiner to combine in-phase sequences of interpolated baseband phased samples of different frequency bands to produce a plurality of sequences of multiband upconverted samples; a pulse encoder to modulate and encode the plurality of sequences of multiband upconverted samples to produce a plurality of encoded multi-band signals; a serializer to convert the plurality of encoded multi-band signals into a RF bitstream; and an E/O interface to convert the RF bitstream to optical signals to output via an optical fiber. a set of input ports to receive baseband samples of a signal to be transmitted on a set of disjoint frequency bands, each input port receives a sequence of baseband samples for transmission on a corresponding RF frequency band; a set of filter banks, comprising one filter bank for each input port, wherein each filter bank includes a plurality of digital polyphase interpolation filters (210, 220, 230) to sample a shifted phase of the corresponding sequence of baseband samples and to interpolate the sampled phases to produce a plurality of sequences of interpolated baseband phased samples with the shifted phase; a set of oscillators banks comprising one oscillator bank for each filter bank, wherein each oscillator bank includes a plurality of polyphase Digital Direct Synthesizer, DDS, corresponding to the plurality of digital polyphase interpolation filters (210, 220, 230) to generate a plurality of sequences of samples of digital waveform comprising one sequence of samples of digital waveform for each of the interpolated baseband phased samples, wherein the sequence of samples of digital waveform is phase synchronized with the corresponding interpolated baseband phased samples, wherein an effective frequency of the digital waveform equals a RF sampling rate divided by the number of the plurality of interpolated baseband phased samples; a set of mixer banks comprising one mixer bank for each filter bank, wherein each mixer bank includes a plurality of parallel digital mixers to mix corresponding sequences of samples of digital waveform and interpolated baseband phased samples to up convert each sequence of interpolated baseband phased samples to the effective frequency; a parallel digital combiner to combine in-phase sequences of interpolated baseband phased samples of different frequency bands to produce a plurality of sequences of multiband upconverted samples; a pulse encoder to modulate and encode the plurality of sequences of multiband upconverted samples to produce a plurality of encoded multi-band signals; a serializer to convert the plurality of encoded multi-band signals into a RF bitstream; and an E/O interface to convert the RF bitstream to optical signals to output via an optical fiber.