The GC5016 is a flexible wideband 4-channel digital up-converter and down-converter. The GC5016 is designed for high-speed, high bandwidth digital signal processing applications like 3G cellular base transceiver station transmit and receive channels. The GC5016 is also applicable for general-purpose digital filtering applications. The four identical processing channels can be independently configured for up-conversion, down-conversion or a combination of two up-conversion and two down-conversion channels.
In up-conversion mode, the channel accepts real or complex signals, interpolates them by programmable amounts ranging from 1 to 4096, and modulates them up to selected center frequencies. The 4 digital up-converter channels signals can be output individually, summed together on one or two outputs on a single GC5016, or optionally summed between multiple GC5016s. Channels can be used in pairs to increase the output sample rate, to increase filtering capacity, to increase the input bandwidth, or any combination. Each channel contains a user programmable input filter (PFIR), which can be used to shape the transmitted signals spectrum, or as a Nyquist transmit filter for shaping digital data such as QPSK, GMSK or QAM symbols.
In down-conversion mode, the channel accepts real or complex signals, demodulates them from selected carrier frequencies, decimates them by programmable amounts ranging from 1 to 4096, applies a gain from a user defined automatic gain control, and produces 20-bit outputs. The frequencies and phase offsets of the four sine/cosine sequence generators can be independently specified, as can the interpolation and filtering of each circuit. Channels can be synchronized to support beam forming or frequency hopped systems. The output from the down-conversion channel is formatted and output in up to four output ports as either real or complex data.