Transmission Mode Allocation in LTE Networks

Patent metadata

Field	Value
Publication number	US-2016164580-A1
Application number	US-201414906460-A
Country	US
Kind code	A1
Filing date	Jul 22, 2014
Priority date	Jul 23, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

The number of active antenna ports used for uplink and/or downlink MIMO transmissions to a given user are dynamically adjusted, based on user data traffic payload size per period of time, and based on RF conditions. An example method, in a radio transceiver that supports two or more MIMO transmission and reception modes, begins with evaluating channel conditions between the radio transceiver and a remote wireless device and comparing a throughput demand for the remote wireless device to a forward link capacity and/or reverse link capacity. A forward link transmission mode or a reverse link transmission mode is changed, based on the channel conditions and the throughput demand. The transmission mode is changed from a first multi-stream mode to a second multi-stream mode having fewer streams than the first multi-stream mode, despite that channel conditions for the corresponding link support the first multi-stream mode.

First claim

1 - 16 . (canceled)

17 . A method, in a radio transceiver that supports two or more Multiple-Input Multiple-Output (MIMO) transmission and reception modes, the method comprising:
evaluating channel conditions between the radio transceiver and a remote wireless device; comparing a throughput demand for the remote wireless device to a forward link capacity or reverse link capacity, or both; based on the channel conditions and the throughput demand, changing a forward link transmission mode or a reverse link transmission mode, or both, from a first multi-stream mode to a second multi-stream mode, the second multi-stream mode having fewer streams than the first multi-stream mode, despite that channel conditions for the corresponding link support the first multi-stream mode.

18 . The method of claim 17 , wherein the first multi-stream mode is a four-stream spatial multiplexing mode and the second multi-stream mode is a two-stream spatial multiplexing mode.

19 . The method of claim 17 , further comprising signaling the remote wireless device to switch from the first multi-stream mode to the second multi-stream mode for a subsequent reverse link transmission, and subsequently receiving data from the remote wireless device according to the second multi-stream mode.

20 . The method of claim 17 , further comprising transmitting, to the remote wireless device, a forward link scheduling message indicating the change from the first multi-stream mode to the second multi-stream mode, and transmitting data to the remote wireless device according to the second multi-stream mode.

21 . The method of claim 17 , wherein evaluating channel conditions between the radio transceiver and a remote wireless device comprises receiving and evaluating channel quality indicators sent by the remote wireless device, or measuring channel conditions based on reference symbols transmitted by the remote wireless device, or both.

22 . The method of claim 17 , further comprising determining the throughput demand by evaluating a forward link buffer corresponding to the remote wireless device, or by receiving and evaluating a buffer status report from the remote wireless device, or both.

23 . The method of claim 17 , wherein changing the forward link transmission mode or the reverse link transmission mode, or both, is based on determining that the throughput demand exceeds a predetermined fraction of a transmission-time-interval capacity.

24 . The method of claim 17 , wherein changing the forward link transmission mode or the reverse link transmission mode, or both, is further based on an aggregate loading of the forward link or reverse link, or both.

25 . A radio transceiver, comprising
radio-frequency (RF) circuitry configured to support two or more Multiple-Input Multiple-Output (MIMO) transmission and reception modes, and a processing circuit configured to control the RF circuitry and to: evaluate channel conditions between the radio transceiver and a remote wireless device; compare a throughput demand for the remote wireless device to a forward link capacity or reverse link capacity, or both; and, based on the channel conditions and the throughput demand, change a forward link transmission mode or a reverse link transmission mode, or both, from a first multi-stream mode to a second multi-stream mode, the second multi-stream mode having fewer streams than the first multi-stream mode, despite that channel conditions for the corresponding link support the first multi-stream mode.

26 . The radio transceiver of claim 25 , wherein the first multi-stream mode is a four-stream spatial multiplexing mode and the second multi-stream mode is a two-stream spatial multiplexing mode.

27 . The radio transceiver of claim 25 , wherein the processing circuit is further configured to control the RF circuitry to signal the remote wireless device to switch from the first multi-stream mode to the second multi-stream mode for a subsequent reverse link transmission, and to subsequently receive data from the remote wireless device according to the second multi-stream mode.

28 . The radio transceiver of claim 25 , wherein the processing circuit is further configured to control the RF circuitry to transmit, to the remote wireless device, a forward link scheduling message indicating the change from the first multi-stream mode to the second multi-stream mode, and to transmit data to the remote wireless device according to the second multi-stream mode.

29 . The radio transceiver of claim 25 , wherein the processing circuit is configured to evaluate channel conditions between the radio transceiver and a remote wireless device by receiving and evaluating channel quality indicators sent by the remote wireless device, or by measuring channel conditions based on reference symbols transmitted by the remote wireless device, or both.

30 . The radio transceiver of claim 25 , wherein the processing circuit is configured to determine the throughput demand by evaluating a forward link buffer corresponding to the remote wireless device, or by receiving and evaluating a buffer status report from the remote wireless device, or both.

31 . The radio transceiver of claim 25 , wherein the processing circuit is configured to change the forward link transmission mode or the reverse link transmission mode, or both, based on determining that the throughput demand exceeds a predetermined fraction of a transmission-time-interval capacity.

32 . The radio transceiver of claim 25 , wherein the processing circuit is configured to change the forward link transmission mode or the reverse link transmission mode, or both, based further on an aggregate loading of the forward link or reverse link, or both.

Assignees

• Ericsson Telefon Ab L M

Inventors

• El-Najjar Jad
• El Chebib Nader
• Joshi Monil

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04W72/085

  Electricity · mapped topic

• H04B7/0413 Primary

  MIMO systems · CPC title

• H04B7/0691

  using subgroups of transmit antennas · CPC title

• H04B7/0686

  Hybrid systems, i.e. switching and simultaneous transmission · CPC title