Apple Inc.
FREQUENCY TRACKING FOR BEAMFORMED SYSTEMS

Abstract:

A method is provided to generate and control transmission of reference symbols in a synchronization subframe, wherein a reference symbol includes reference values mapped to a block of K subcarriers. The method includes generating data corresponding to a basic subsequence of K-R1-R2 reference values, where R1 and R2 are integers such that 1.ltoreq.R1+R2<K, and mapping the data corresponding to the basic subsequence to an original range of K-R1-R2 contiguous subcarriers in the block such that there is a first set of R1 unmapped subcarriers above the original range of subcarriers and a second set of R2 unmapped subcarriers below the original range of subcarriers. Data corresponding to last R1 values in the basic subsequence is mapped to the first set of unmapped subcarriers. Data corresponding to first R2 values in the basic subsequence is mapped to the second set of unmapped subcarriers.