The installation and maintenance company, a recent acquisition of engineering and underwater services provider Global Marine Group (GMG), will carry out the installation, which is scheduled to be completed later this month.
The 96-fibre armoured cable will be supplied by fibre communication technology group Hexatronic and will run from the shore to the project's offshore substation.
CWind managing director, Lee Andrews, said: "In a very tight timeframe, the CWind team has engineered a solution for a complex project that accommodates the existing on-site infrastructure.
GMG announced the takeover of CWind in December 2016, having acquired a majority interest in the company in February of that year.
The Rampion project is part-owned by the Green Investment Bank and Canadian energy company Enbridge, with E.on holding a majority stake.
Plans for the site received approval from the Crown Estate in January 2010. The Rampion offshore wind farm is set to include 116 Vestas V112-3.45MW turbines.