Time and frequency acquisition and tracking for OFDMA wireless systems

摘要

Obtaining a timing reference in wireless communication is facilitated when desiring to communicate with a weak serving base station (such as an evolved NodeB) in the presence of a stronger interfering base station. The user equipment (UE) may track a stronger interfering base station's timing, or the UE may track a timing that is derived by a composite power delay profile (PDP) from multiple base stations. The composite PDP may be constructed by adjusting individual base station PDPs according to a weighting scheme. The timing obtained in such a manner may be used for estimation of the channel of the interfering base station and cancelling interfering signals from the base station. It may also be used to estimate the channel of the serving base station after adding a backoff. The UE may track a stronger interfering base station's frequency, or the UE may track a composite frequency.

主权项

1. A method operable to acquire a timing of a serving base station in presence of interference from an interfering base station, the method comprising:
acquiring a first reference signal from a first base station, wherein the first base station is the interfering base station; constructing a first power delay profile (PDP) from the first reference signal; acquiring a second reference signal from a second base station, wherein the second base station is the serving base station and the second reference signal is weaker than the first reference signal; constructing a second PDP from the second reference signal; constructing a composite PDP from the first and second PDPs; generating a timing reference for a combined signal from the composite PDP; determining the timing of the weaker serving base station based at least in part on the timing reference for the combined signal; and tracking and using the determined timing as a timing reference for communicating with the weaker serving base station.