Method, device and test setup for implementing carrier aggregation

Abstract

There is provided a method of implementing carrier aggregation on a first transceiver. The method comprises receiving and decoding, during a first subframe, channel quality information from user equipment and transferring, before the expiry of a second subframe immediately following the first subframe, the decoded channel quality information over a direct physical link to a second transceiver, for use in decoding further channel quality information from the user equipment.

Claims

1. A method of implementing carrier aggregation on a first transceiver in a test setup to examine performance of user equipment, the method comprising: receiving and decoding at the first transceiver, during a first subframe, channel quality information from the user equipment, and transferring, before expiry of a second subframe immediately following the first subframe, the decoded channel quality information over a direct physical link to a second transceiver, for use by the second transceiver in decoding further channel quality information from the user equipment.

2. The method of claim 1, wherein the direct physical link comprises a serial peripheral interface link, and the method further comprises controlling the serial peripheral interface link to perform the transfer of decoded channel quality information.

3. A first transceiver configured to implement carrier aggregation in a test setup to examine performance of user equipment, the first transceiver comprising: a receiver portion configured to receive and decode, during a first subframe, channel quality information from user equipment, and to transfer, before expiry of a second subframe immediately following the first subframe, the decoded channel quality information over a direct physical link to a second transceiver, the decoded channel quality information being useable by the second transceiver to decode further channel quality information from the user equipment.

4. A test setup configured to examine performance of user equipment operating according to one or more predefined standards, the test setup comprising: the first transceiver of claim 3, configured to emulate a base station and to communicate with the user equipment under test according to a predefined test script representing a configuration scenario.

5. The test setup of claim 4, further comprising the second transceiver connected to the first transceiver by the direct link, at least one further transceiver and at least one further direct link the first transceiver, the second transceiver and the at least one further transceiver in a daisy chain.

6. A non-transitory computer-readable medium storing instructions, executable by a computer processor, for performing the method of implementing carrier aggregation of claim 1.

7. A method of examining performance of user equipment operating according to one or more predefined standards, the method comprising: emulating a base station using a first transceiver configured to communicate with the user equipment under test according to a predefined test script representing a configuration scenario; and receiving and decoding, during a first subframe, channel quality information from user equipment, and transferring, before expiry of a second subframe immediately following the first subframe, the decoded channel quality information over a direct physical link from the first transceiver to a second transceiver, for use in decoding further channel quality information from the user equipment.

8. The transceiver of claim 3, wherein the direct physical link comprises a serial peripheral interface link, and the first transceiver is configured to control the serial peripheral interface link to perform the transfer of the decoded channel quality information.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A description will now be given, by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a diagram illustrating a test setup running a protocol compliance toolset being used to examine conformance of user equipment with predefined standards;

(3) FIG. 2 is a flowchart representing part of a method of implementing carrier aggregation.

DETAILED DESCRIPTION

(4) The test setup 100 comprises a control PC 102 for effecting overall control of the system, an Ethernet switch 106 managed by a controller/scheduler 104 for handling communications between the transceivers, and three transceivers being a first transceiver 108, a second transceiver 110 and a third transceiver 112. Although FIG. 1 shows three transceivers, it is to be understood that any number of transceivers can be interconnected depending on the carrier aggregation scenario, with for example anywhere between 2-5 transceivers being interconnected.

(5) User equipment 114 under test is also shown, and communicates with the first transceiver 108 using a first RF link with the second transceiver 110 using a second RF link RF#2, and with the third transceiver 112 using a third RF link RF#3. The first transceiver 108 emulates a first component carrier, the second transceiver 110 emulates a second component carrier, and the third transceiver 112 emulates a third component carrier.

(6) As part of LTE-Advanced Carrier Aggregation the user equipment 114 may be simultaneously connected to multiple component carriers to increase data rates, and the protocol compliance toolset implements emulation scenarios for Carrier Aggregation, with the interconnected multiple transceivers 108, 110, 112 implementing the physical layer of the aggregated Component Carriers under the control of the controller/scheduler 104 via the Ethernet switch 106.

(7) The control and configuration of the physical layer as implemented on the multiple transceivers 108, 110, 112, along with the scheduling of user data, are performed by the controller/scheduler 104.

(8) When in a connected state with the network, the user equipment 114 can be configured to periodically send channel status information about the quality of the channel as affected by propagation conditions and interfering sources. Such channel status information may include.

(9) a) Rank Indicator/Precoding Type Indicator (RI/PTI) hits, which indicate the optimum number of independent downlink data streams which can be received at the UE;

(10) b) Channel Quality Indicator/Precoding Matrix Indicator (CQI/PMI) bits, which provide a measure of the interference conditions and preferred ratios of information bits versus channel capacity (channel coding rate).

(11) Depending on scheduler operation, uplink transmissions from the user equipment 114 can be scheduled on component carriers emulated on separate transceivers 108, 110, 112 in consecutive subframes. Under specific configuration conditions, decoded RI/PTI bits received from the user equipment 114 in a particular subframe can be necessary for decoding CQI/PMI bits in the very next subframe.

(12) In order to reduce the latency of sharing the RI/PTI values across the multiple transceivers 108, 110, 112, each of the transceivers 108, 110, 112 is provisioned with a dedicated, direct physical link, in the form of a Serial Peripheral interface (SPI) link 116, for interconnecting the transceivers 108, 110, 112 in a daisy-chain fashion. RI/PTI values decoded on each transceiver 108, 110, 112 are shared amongst the multiple transceivers participating in Carrier Aggregation using the SPI link 116, for example by being broadcast to all transceivers 108, 110, 112 along the daisy chair. Three such SPI links 116 interconnecting the three transceivers 108, 110, 112 are shown in FIG. 1.

(13) FIG. 2 shows part of a method of implementing carrier aggregation. The method includes decoding RI/PTI bits (202), before determining (204) whether or rot to transmit (206) the decoded RI/PTI bits to a further transceiver over the SPI link 116. The determination (204) may depend on higher layer configuration as defined by test script/configuration whether the transceiver is part of a carrier aggregation set. This information is available to the controller/scheduler 104 as part of configuration information. The received, decoded RI/PTI bits may be used in an update by the receiving transceiver (208), before being used to decode CQI values (210). The controller/scheduler 104 may provide configuration information determining whether the update (208) needs to be executed on a particular transceiver for a particular subframe. In a parallel pathway, the decoded RI/PTI bits are used in an update at the decoding transceiver (212), since, depending on the test configuration, the CGI/PMI can be received on the same transceiver as that on which the RI/PTI was received.

(14) It will be appreciated that the aforementioned circuitry may have other functions in addition to the mentioned functions, and that these functions may be performed by the same circuit.

(15) The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the an that various modifications may be made within the scope of the invention.