US 9,866,301 B2Granted

Channel estimation techniques for LSAS backhaul and the like

AssigneeAlcatel Lucent

InventorsLi Erran Li, Holger Claussen

Life of this patent

Estimating the term…

Loading patent…

Abstract

In certain embodiments, a macrocell base station (BS), such as an LSAS BS, estimates its backhaul channels with a small-cell BS (e.g., a relay or repeater) by averaging multiple instances of a received pilot signal repeatedly transmitted by the small-cell BS. Since the macrocell and small-cell BSs are stationary, averaging the received pilot signal transmissions over time results in the zero-temporal-mean time-dependent component of each backhaul channel as well as zero-temporal-mean noise and interference signals from other wireless nodes to substantially cancel out, enabling the macrocell BS to relatively infrequently estimate a relatively time-invariant, dominant component for each backhaul channel. The macrocell BS uses the estimated dominant components to generate user-data-based downlink transmissions to the small-cell BS. In this way, the processing to estimate channel state information (CSI) data for the backhaul channels is greatly reduced compared to conventional techniques.

Claims14

Dependent claims

A method comprising:

(a) a first antenna of a first wireless node of a wireless communications system receiving multiple instances of a pilot signal from a second wireless node over a first wireless transmission channel;
(b) the first wireless node generating an average received pilot signal from the multiple received instances of the pilot signal;
(c) the first wireless node estimating channel state information (CSI) data for the first wireless transmission channel based on the average received pilot signal;
and
(d) the first wireless node generating signals to be transmitted from the first antenna of the first wireless node via the first wireless transmission channel toward the second wireless node based on the estimated CSI data for the first wireless transmission channel, wherein:
the wireless communications system is a cellular communications system;
the first wireless node is a macrocell base station (BS) of the cellular communications system;
the second wireless node is a small-cell BS of the cellular communications system;
the macrocell BS has multiple macrocell antennas;
the small-cell BS has one or more small-cell antennas;
and
steps (a)-(d) are repeated for each wireless transmission channel between each different macrocell antenna and each different small-cell antenna.

9 more elements

A macrocell base station for a communications system further comprising one or more small-cell base stations, the macrocell base station comprising:

a plurality of macrocell antennas, each macrocell antenna configured to (i) transmit downlink signals to the one or more small-cell base stations and (ii) receive uplink signals from the one or more small-cell base stations;
and
macrocell transceiver circuitry configured to process the uplink signals received by the plurality of macrocell antennas and generate the downlink signals transmitted by the plurality of macrocell antennas, wherein the transceiver circuitry is configured to:
(a) process received uplink signals corresponding to pilot signals transmitted by the one or more small-cell base stations;
(b) generate, for each backhaul channel between a small-cell antenna and a macrocell antenna, a corresponding average received pilot signal over a plurality of different time periods;
(c) generate estimated channel state information (CSI) data for each backhaul channel based on the corresponding average received pilot signal;
and
(d) generate downlink signals to be transmitted by the plurality of macrocell antennas to the one or more small-cell base stations based on the estimated CSI data for the backhaul channels.

5 more elements

Dependencies are inferred from the claim text.