  Resource coordination and interference management is the key to achieving the
benefits of femtocell networks. Over-the-air signaling is one of the most
effective means for distributed dynamic resource coordination and interference
management. However, the design of this type of signal is challenging. In this
paper, we address the challenges and propose an effective solution, referred to
as coded single-tone signaling (STS). The proposed coded STS scheme possesses
certain highly desirable properties, such as no dedicated resource requirement
(no overhead), no near-and-far effect, no inter-signal interference (no
multi-user interference), low peak-to-average power ratio (deep coverage). In
addition, the proposed coded STS can fully exploit frequency diversity and
provides a means for high quality wideband channel estimation. The coded STS
design is demonstrated through a concrete numerical example. Performance of the
proposed coded STS and its effect on cochannel traffic channels are evaluated
through simulations.
