High sensitivity reception is a crucial problem of fiber radio links. A significant improvement is obtained by applying a new approach called optical-microwave double mixing. The new approach can provide as much as 30 dB of higher mixing product in a narrow-band compared with the direct detection applying only additional passive components. Detailed investigation of the optical-microwave double-mixing method is shown to get optimum adjustment for specific applications. The new method is advantageously used for the reception of subcarrier-multiplexed optical signals.