Scaling signal voltage
There is a class of basic gates called "level-translating" logic, or "level shifters", or a combination thereof. An example is SN74LV1G34,
With Vcc set to 6V, the circuit will accommodate your "7-V" signal, and produce clean output signal, works up to 50 MHz though. You might need to search for faster ICs. This would be a technically clean solution.

However, depending on your source and receiver, a simple diode limiter with a 100-Ohm series resistor will do the job as well. Or maybe even nothing is needed.