Managing TDD-FDD interference

In many urban and semi-rural areas new base station sites can be difficult to obtain leading to new operators being required to share sites with existing operators. In addition local environmental and planning regulations can also lead to a preference for site sharing.

In such circumstances it is generally necessary to minimize inter-network interference especially between TDD and FDD systems operating in adjacent spectrum blocks. Some regulations seek to limit emissions from one network spectrum block into an adjacent network block but do not address the co-sited base station situation.

This WiMAX Forum paper reports an analysis and measurement campaign which concludes that inter-network interference between co-sited base stations can be readily reduced to a manageable level with minimal impact on system capacity through careful antenna siting during deployment. Co-sited base station operation is entirely possible even between TDD and FDD (or TDD) system adjacencies.

This white paper originally published on the WiMAX Forum