Determining error vector magnitude for a single layer transmission using a multiple-input multiple-output receiver
Apparatuses, methods, and systems are disclosed for calculating an error vector magnitude (“EVM”) of a transmitter. An apparatus includes a transceiver that receives, using an unbiased linear multiple-input multiple-output (“MIMO”) receiver, a single layer transmission signal transmitted via a propagation channel, the signal generated and transmitted using an antenna port at a transmitter, the antenna port comprising a plurality of antennas and an antenna connector for each of the plurality of antennas and a processor that determines an EVM for the single layer transmission from the transmitter based on an output of the unbiased linear MIMO receiver, the EVM defined as 100 times a square root of a mean-square error at the output of the unbiased linear MIMO receiver.
1 . A method performed by a user equipment (“UE”), the method comprising:
receiving a single layer transmission signal via a propagation channel, wherein the single layer transmission signal is generated and transmitted using an antenna port comprising a plurality of antennas and an antenna connector for each of the plurality of antennas; and
defining an error vector magnitude (“EVM”) for transmit diversity of the single layer transmission signal using at least two of the plurality of antennas, wherein the EVM is expressed as a power-weighted combination or per-antenna EVM value.
2 . The method of claim 1 , wherein the EVM is defined as 100 times a square root of a mean square error as an output of a receiver that is a zero-forcing unbiased linear multiple-input multiple-output (“MIMO”) receiver.
3 . The method of claim 1 , further comprising expressing a mean square error in terms of a correlation matrix of transmitter noise at an output of the plurality of antennas.
4 . The method of claim 1 , further comprising expressing the EVM as a function of power transmitted on each of the plurality of antennas comprising the antenna port and measuring the EVM at each of the plurality of antennas.
5 . The method of claim 1 , wherein the antenna port comprises two transmit antennas, the EVM for the single layer transmission given by:
EVM
=
P
1
EVM
1
+
P
2
EVM
2
P
1
+
P
2
where EVM 1 and EVM 2 are the EVM values for first and second transmit antennas of the plurality of antennas comprising the antenna port and P 1 and P 2 are values of transmit power on the first and second transmit antennas.
6 . A user equipment (“UE”) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive a single layer transmission signal via a propagation channel, wherein the single layer transmission signal is generated and transmitted using an antenna port comprising a plurality of antennas and an antenna connector for each of the plurality of antennas; and
define an error vector magnitude (“EVM”) for transmit diversity of the single layer transmission signal using at least two of the plurality of antennas, wherein the EVM is expressed as a power-weighted combination or per-antenna EVM value.
7 . The UE of claim 6 , wherein the EVM is defined as 100 times a square root of a mean square error as an output of a receiver that is a zero-forcing unbiased linear multiple-input multiple-output (“MIMO”) receiver.
8 . The UE of claim 6 , wherein the at least one processor is configured to cause the UE to express a mean square error in terms of a correlation matrix of transmitter noise at an output of the plurality of antennas.
9 . The UE of claim 6 , wherein the at least one processor is configured to cause the UE to express the EVM as a function of power transmitted on each of the plurality of antennas comprising the antenna port and measuring the EVM at each of the plurality of antennas.
10 . The UE of claim 6 , wherein the antenna port comprises two transmit antennas, the EVM for the single layer transmission given by:
EVM
=
P
1
EVM
1
+
P
2
EVM
2
P
1
+
P
2
where EVM 1 and EVM 2 are the EVM values for first and second transmit antennas of the plurality of antennas comprising the antenna port and P 1 and P 2 are values of transmit power on the first and second transmit antennas.
11 . A user equipment (“UE”) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive a single layer transmission signal via a propagation channel, the single layer transmission signal associated with an antenna port comprising a plurality of antennas and an antenna connector for each of the plurality of antennas; and
define error vector magnitude (“EVM”) for transmit diversity of the single layer transmission signal using two antennas of the plurality of antennas, the EVM given by:
EVM
=
P
1
EVM
1
+
P
2
EVM
2
P
1
+
P
2
where EVM 1 and EVM 2 are EVM values for first and second transmit antennas of the plurality of antennas comprising the antenna port and P 1 and P 2 are values of transmit power on the first and second transmit antennas.
12 . The UE of claim 11 , wherein the EVM values EVM 1 and EVM 2 for the first and second transmit antennas are a function of the values of transmit power P 1 and P 2 for the first and second transmit antennas.
13 . The UE of claim 11 , wherein the at least one processor is configured to cause the UE to receive the single layer transmission signal using a zero-forcing unbiased linear multiple-input multiple-output (“MIMO”) receiver.
14 . The UE of claim 13 , wherein the at least one processor is configured to cause the UE to determine the EVM for the single layer transmission signal, the EVM defined as 100 times a square root of a mean square error at an output of a receiver of the UE.
15 . The UE of claim 14 , wherein the at least one processor is configured to cause the UE to express the mean square error in terms of a correlation matrix of transmitter noise at an output of the plurality of antennas.
16 . A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
receive a single layer transmission signal via a propagation channel, wherein the single layer transmission signal is generated and transmitted using an antenna port comprising a plurality of antennas and an antenna connector for each of the plurality of antennas; and
define an error vector magnitude (“EVM”) for transmit diversity of the single layer transmission signal using at least two of the plurality of antennas, wherein the EVM is expressed as a power-weighted combination or per-antenna EVM value.
17 . The processor of claim 16 , wherein the EVM is defined as 100 times a square root of a mean square error as an output of a receiver that is a zero-forcing unbiased linear multiple-input multiple-output (“MIMO”) receiver.
18 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to express a mean square error in terms of a correlation matrix of transmitter noise at an output of the plurality of antennas.
19 . The processor of claim 16 , wherein the at least one controller is configured to cause the processor to express the EVM as a function of power transmitted on each of the plurality of antennas comprising the antenna port and measuring the EVM at each of the plurality of antennas.
20 . The processor of claim 16 , wherein the antenna port comprises two transmit antennas, the EVM for the single layer transmission given by:
EVM
=
P
1
EVM
1
+
P
2
EVM
2
P
1
+
P
2
where EVM 1 and EVM 2 are the EVM values for first and second transmit antennas of the plurality of antennas comprising the antenna port and P 1 and P 2 are values of transmit power on the first and second transmit antennas.