Time and frequency synchronization
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsHavish Koorapaty, Mattias Frenne, Daniel Larsson, Jiann-Ching Guey, Jung-Fu Cheng
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Abstract
The scheduling flexibility of CSI reference signals enables time and frequency synchronization using multiple non-zero CSI-RSs transmitted in the same subframe, or using CSI-RSs transmitted in the same subframe with other synchronization signals. Also, multiple synchronization signals may be scheduled in the same subframe to enable fine time and frequency synchronization without cell-specific reference signals.
Claims17
A method of transmitting and receiving reference signals for synchronization in an Orthogonal Frequency Division Multiplexing (OFDM) system, said method comprising:
- transmitting, at a network node, a first channel state information (CSI) reference signal in a first portion of each of at least one of a plurality of regularly spaced time periods in accordance with a first configuration of transmission resources, wherein the first configuration of transmission resources defines a first allocation of time and frequency resources for the first CSI reference signal;
- receiving, at a user terminal, the first CSI reference signal in the first portion of each of the at least one of the plurality of regularly spaced time periods;
- transmitting, at the network node, a second CSI reference signal in a second portion of each of the at least one of the plurality of regularly spaced time periods in accordance with a second configuration of transmission resources, wherein the second configuration of transmission resources defines a second allocation of time and frequency resources for the second CSI reference signal;
- and
- receiving, at the user terminal, the second CSI reference signal in the second portion of each of the at least one of the plurality of regularly spaced time periods,
- wherein transmitting the first CSI reference signal in accordance with the first configuration and transmitting the second CSI reference signals in accordance with the second configuration comprises transmitting the first and second CSI reference signals from the same antenna port in both the first portion and the second portion of each of the at least one of the plurality of regularly spaced time periods,
- synchronizing, at the user terminal, with the OFDM system using the first and second CSI reference signals received during each of the at least one of the plurality of regularly spaced time periods.
An Orthogonal Frequency Division Multiplexing (OFDM) telecommunications system comprising one or more base stations and one or more user terminals, said one or more base stations comprising:
- transceiver circuitry configured to communicate with the one or more user terminals over a wireless communication channel;
- and
- control circuitry configured to providing reference signals for transmission to the one or more user terminals via the transceiver circuit, said control circuitry being configured to:
- transmit a first channel state information (CSI) reference signal in a first portion of at least one of a plurality of regularly spaced time periods;
- transmit a second CSI reference signal in a second portion of the at least one of the plurality of regularly spaced time periods;
- and
- wherein the first and second CSI reference signals are transmitted from the same antenna port to ensure the user terminal in the OFDM system can utilize the first and second CSI reference signals for synchronization assistance.
Dependencies are inferred from the claim text.