Methods and apparatus for cyclic prefix reduction in MMwave mobile communication systems

摘要

To reduce the duration of a cyclic prefix used for a multiple input, multiple output (MIMO) communications channel, delay spread variations for different transmit/receive beam pair combination is estimated and used for fast beam switching and to support single user MIMO (SU-MIMO) even when the CP difference between two beams is large. Beam switching reference signals are employed to estimate delay spread exceeding current CP, and to support beam switching. CP covering sub-clusters within clusters for the MIMO channel are exploited to reduce the CP requirement and improve efficiency. Any one of a number of different CP durations may be selected for each different mobile station, using one of a finite set of subframe configurations for which the CP durations of different symbol locations within the subframe are predefined. Dynamically switching subframe configurations by the system accommodates high mobility.

主权项

1. A method, comprising:
inserting, by a transmitter, a beam switching reference signal in an Orthogonal Frequency Division Multiplexing (OFDM) signal for transmission to a mobile station in a Multiple Input, Multiple Output (MIMO) wireless communications system; and estimating delay spread, of new beams, exceeding a current cyclic prefix of the OFDM signal using the beam switching reference signal, wherein the beam switching reference signal comprises a plurality of different time domain Zadoff Chu (ZC) sequences each based on one of a plurality of different sequence roots, wherein the ZC sequences based on the different sequence roots are inserted between sets of contiguous resource blocks in time and frequency within the OFDM signal.