3 WLAN Mode
3.7 WLAN MIMO Modulation Analysis Measurement
View Marker Operation
Channel Matrix No
3.7.3.9 Stream Results Summary
Shows the stream numeric summary results.
The Stream Results Summary window appears in the following View:
View Marker Operation
Stream Results Summary No
3.7.3.10 Channel Results Summary
Shows the stream numeric summary results.
CrossPwr
The CrossPwr values in the OFDM Error Summary is the average of the power level
of the err1 terms and of the err2 terms for all subcarriers.
Currently, there are 2 data streams and 2 input channels. The simplest case has
stream1 connected directly to input1, and stream2 connected directly to input2.
This is called a "Direct Map" setup. In this case, the channel response matrix at each
subcarrier ideally becomes:
[1 0]
[0 1]
However, in a real transmitter there will be leakage of stream1 into transmitter2, and
stream2 into transmitter1, resulting in a channel response matrix that looks more
like:
[~1 err1]
[err2 ~1]
The err1 and err2 terms represent the leakage. There is a matrix like this for each
subcarrier in the system. The CrossPwr values in the OFDM Error Summary is the
average of the power level of the err1 terms and of the err2 terms for all subcarriers.
The values are normalized so that Ch1 CrossPwr is the ratio of stream2power /
stream1power present on channel1, and Ch2 CrossPwr is the ratio of stream1power
/ stream2power present on channel2.
For a transmitter in Direct Map mode, the ideal value for the CrossPwr is 0 (-780dB).
The actual value provides a useful measure of how much crosstalk is present
between the two RF chains of the transmitter. If the transmitter is not in Direct Map
mode, then the ideal values for the CrossPwr will no longer be zero but will instead
1141 WLAN Mode User's &Programmer's Reference
To Next Page