Non-orthogonal multiple access (NOMA) is one of the most promising multiple access schemes, which is anticipated to improve the network spectral efficiency in 5G wireless cellular networks. Together with joint-transmission coordinated multi-point transmission (JT-CoMP), a JT-CoMP-NOMA network will also improve the data rates of cell-edge users, which are prone to severe inter-cell interference. In this paper we propose an implementation of the centralized resource allocation problem for JT-CoMP- NOMA in GAMS, where the aim is to perform joint sub-carrier assignment and power allocation in multi-cell downlink NOMA networks. The implementation serves as a benchmark for evaluating the network sum-rate performance of resource allocation algorithms for JT-CoMP-NOMA systems. Moreover, the provided implementation incorporates practical constraints, such as the maximum number of users multiplexed over each sub-carrier, SIC decoding order, user pairing, intra- and inter-cell interference, and minimum rate requirements. Simulation results are presented as a proof of concept.