Disable rate control in linux wireless driver

I need to evaluate the performance of a few wireless cards at different bitrates. I found out that "minstrel" algorithm continuously adjusts this rate. 1. Can someone point me to 'how I can manually set the bit-rate for these wireless cards'? NOTE: I used iwconfig wlan0 rate 54M fixed but that was of no use. (Please see https://superuser.com/questions/870779/iwlist-wlan0-bitrate-says-unknown-bit-rate-information/) 2. Is this of any help to me? CONFIG_MAC80211_HAS_RC=y