An external clock is fed to all the MicroTCA chassis. The CLK IN module feeds the clock signal to the MCH (MicroTCA Control Hub) which distributes it to the Perseus AMC throughout the chassis via the backplane. This ensures that all Perseus cards are using the same clock.
The MCH is equipped with a GPS receiver used to time-stamp the digital samples to facilitate MAC layer development, providing it with the right tools to send and receive data bursts at the right time. The red path in the figure illustrates the clocking scheme, while the blue path represents the pulse-per-second used for time-stamping.
The system above guarantees than each Radio420M modules will be phased lock, enabling MIMO algorithm implementation after calibration of the system using phase alignment corrections.