Optimal bidirectional amplifier placement method for stable radio frequency reference dissemination

Abstract

The network for stable radio frequency dissemination is evolving from point-to-point to point-to-multipoint. For a long-distance dissemination network with multiple access sites, the amplifier is one of the most important components which is used to compensate for power loss caused by optical fibers and optical couplers when the RF reference propagates through dissemination networks. However, the amplifier also introduces amplified spontaneous emission (ASE) noise which will degrade the stability of RF reference, and can not be eliminated by any compensation methods. Hence, this paper aims to find proper amplifiers to minimize total phase jitters corresponding to the stability of RF reference signal for long-distance ring dissemination network with multiple access sites. First, a non-linear noise model of ring dissemination network constrained by several non-linear and linear factors is formulated. Then three optimal amplifier placement and maximum gain adjustment strategies are proposed, i.e., as maximum as possible placement (AMAP), as compatible as possible placement (ACAP), and as average as possible placement (AAAP). Finally, numerical results conducted in various long-distance ring dissemination networks demonstrate that AAAP outperforms AMAP and ACAP for different download sites. The phase jitters of AAAP can decrease approximately 14% than ACAP. Besides, the performance of AAAP still better than AMAP and ACAP for different long-distance dissemination networks and remote sites. Moreover, the performance of three optimal placement strategies is not sensitive to the max achievable gain of amplifiers. More importantly, the AAAP consumes fewer amplifiers than AMAP and ACAP, and the difference in the number of amplifiers will increase with the number of sites located in long-distance ring dissemination networks. These results can provide significant guidance to stable RF dissemination network planning in the future.