QUALCOMM Incorporated
NPRACH having improved reliability performance

Abstract:

NPRACH suffers from false alarms in which a base station detects and cannot distinguish an NPRACH signal that is intended for a different base station. An NPRACH may include a cell specific frequency shift pattern over repetitions and/or a repetition level scrambling sequence that enables a base station to more accurately detect NPRACH. An apparatus generates an NPRACH signal comprising multiple repetitions, wherein each repetition comprises multiple symbol groups. The apparatus may apply a different frequency shift between repetitions of the NPRACH signal. The frequency shift may comprise a cell specific random frequency shift pattern applied over each repetition. The apparatus may apply a repetition level scrambling sequence to the NPRACH signal, wherein a single scrambling sequence is applied to a set of repetitions comprised in the NPRACH signal. The apparatus transmits the NPRACH to a serving cell.