Frequency division duplex (FDD) massive MIMO backhaul for repeater small cells
First Claim
1. A method for channel estimation in a massive multiple-input-multiple-output (MIMO) backhaul system, the method comprising:
- transmitting, by a central node of the MIMO backhaul system to a small cell repeater terminal on the downlink, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain, each pilot sequence in the set of pilot sequences corresponding to an antenna of an antenna array at the central node;
receiving, at the central node, an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal on the uplink, the received uplink pilot signal being a frequency converted retransmission of the downlink pilot signal; and
estimating at least one of an uplink channel and a downlink channel between the central node and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal.
3 Assignments
0 Petitions
Accused Products
Abstract
In a method for transmitting data through a Massive MIMO backhaul system, a central node of the MIMO backhaul system transmits, to a small cell repeater terminal on the downlink, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain. Each pilot sequence in the set of pilot sequences corresponds to an antenna of an antenna array at the central node. The central node receives an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal on the uplink, where the received uplink pilot signal is a frequency converted retransmission of the downlink pilot signal. The central node estimates at least one of an uplink channel and a downlink channel between the central node and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal.
9 Citations
21 Claims
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1. A method for channel estimation in a massive multiple-input-multiple-output (MIMO) backhaul system, the method comprising:
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transmitting, by a central node of the MIMO backhaul system to a small cell repeater terminal on the downlink, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain, each pilot sequence in the set of pilot sequences corresponding to an antenna of an antenna array at the central node; receiving, at the central node, an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal on the uplink, the received uplink pilot signal being a frequency converted retransmission of the downlink pilot signal; and estimating at least one of an uplink channel and a downlink channel between the central node and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A Massive multiple-input-multiple-output (MIMO) central node, comprising:
- a Massive MIMO antenna array configured to,
transmit, to a small cell repeater terminal, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain, each pilot sequence in the set of pilot sequences corresponding to an antenna of the Massive MIMO antenna array, and receive an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal, the received uplink pilot signal being a frequency converted retransmission of the downlink pilot signal; and a measurement extraction circuit configured to estimate at least one of an uplink channel and a downlink channel between the Massive MIMO antenna array and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
- a Massive MIMO antenna array configured to,
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21. A small cell repeater terminal for transmitting data through a massive multiple-input-multiple-output (MIMO) backhaul system, the terminal comprising:
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a transceiver antenna configured to, receive a trigger signal from a central node of the massive MIMO backhaul system on a downlink channel, receive, from the central node, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain, each pilot sequence in the set of pilot sequences corresponding to an antenna of a Massive MIMO antenna array at the Massive MIMO central node, and transmit, to the central node, an uplink pilot signal carrying the set of pilot sequences on the uplink; and a shifter circuit configured to, cause the small cell repeater terminal to enter a training mode in response to the received trigger signal, and in the training mode, frequency convert the received downlink pilot signal to generate the uplink pilot signal carrying the set of pilot sequences.
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Specification