You are not logged in.
Hello all,
I want to change WARP v3 with the 802.11 refence design in a way that transmits signal via RFA only and recives signal via RFB only.
So I tried to change value of 'WLAN_DEFAULT_TX_ANTENNA' and 'WLAN_DEFAULT_RX_ANTENNA' in wlan_mac_ap.c. (in 802.11 Reference Design v1.7.1)
But when I changed values like below examples, there are some problems like '1)' and '2)'.
1) WLAN_DEFAULT_TX_ANTENNA = TX_ANTMODE_SISO_ANTA, WLAN_DEFAULT_RX_ANTENNA = RX_ANTMODE_SISO_ANTB
=> When RFB antenna was disconnected, this AP node can communicate without any problems. (No packets were generated and transmitted when only RFB was connected.)
2) WLAN_DEFAULT_TX_ANTENNA = TX_ANTMODE_SISO_ANTB, WLAN_DEFAULT_RX_ANTENNA = RX_ANTMODE_SISO_ANTA
=> When RFA antenna was disconnected, this AP node can communicate without any problems. (No packets were generated and transmitted when only RFA was connected.)
3) WLAN_DEFAULT_TX_ANTENNA = TX_ANTMODE_SISO_ANTA, WLAN_DEFAULT_RX_ANTENNA = RX_ANTMODE_SISO_ANTA
=> This AP node use only RFA antenna.
4) WLAN_DEFAULT_TX_ANTENNA = TX_ANTMODE_SISO_ANTB, WLAN_DEFAULT_RX_ANTENNA = RX_ANTMODE_SISO_ANTB
=> This AP node use only RFB antenna.
In cases of '1)' and '2)', it seems to use only one antenna for trasmitting and receiving signal, even though values are changed.
How to change the 802.11 refence in a way that transmits signal via RFA only and recives signal via RFB only?
Thanks.
Last edited by wckim (2017-Jul-26 08:43:18)
Offline
Changing those macros should be all that's necessary, with one exception. The DCF will always transmit control responses (CTS, ACK) via the RF interface on which the triggering packet (RTS, DATA) was received. You would need to modify the CTS/ACK Tx code to change this behavior.
When you change the macros for configuration (1) above, what do you see on the LEDs on the WARP v3 board near the RF interfaces? There are 4 LEDs, two per interface. In each pair the red indicates Rx is active, green for Tx. In (1) above you should see the RF B red LED on solidly and the RF A green LED blinking (briefly) for each Tx. The other LEDs (RF B green, RF A red) should be off.
Also, when you say "antenna disconnected", do you terminate the unused RF interface?
Offline
I would need to modify the CTS/ACK tx code.
For your answer, I could change DCF code and check LED lights and succeed.
Also, when you say "antenna disconnected", do you terminate the unused RF interface?
=> No, I didn't terminate unused interface, I just disconnected it.
Sorry, my answer is too late.
Thank you so much.
Offline
No, I didn't terminate unused interface, I just disconnected it.
It is good practice to always terminate the RF interfaces into a 50ohm load, either with an antenna, or cabled to test equipment, or with the 50ohm terminators included with the WARP v3 kit. Transmitting into an unterminated interface will (at best) leak energy or (at worst) damage the RF circuits.
Offline