Performance evaluation of cloud-ran system with carrier frequency offset

Increasing capacity and reducing Capital Expenditures (CAPEX) and Operating Expense (OPEX) are dilemmas for most mobile network operators. As one of the most promising solutions, Cloud Radio Access Network (CRAN) can improve capacity and coverage in a cost effective approach. To evaluate the performance of CRAN in a non-ideal channel with carrier frequency offset (CFO), a model of inter-transmission point (TP) CFO suitable for large-scale cooperative network is studied. Verified by system level evaluation, it can be observed that the performance of CRAN is sensitive to non-ideal channel with CFO in large cooperation size scenario. When inter-TP CFO does not exceed ±3~5ppb, CRAN can still achieve remarkable performance gain on both capacity and coverage even in nonideal channel. Thus, choice of cooperation size should be carefully balanced between performance gain and complexity of hardware design and implementation.