This paper draft presents a study of optical upconversion schemes for mmWave OFDM signals over ARoF systems. The authors propose and compare two configurations of optical doublers and quadruplers that use low-frequency RF sources and Mach-Zehnder modulators to generate and transport high-frequency mmWave signals over 2 km of fiber. The paper evaluates the performance of the schemes for different modulation formats and bandwidths, and discusses the advantages and challenges of each configuration.