From: Performance limits of conventional and widely linear DFT-precoded-OFDM receivers in wideband frequency-selective channels
Receiver type
Gap for N r = 1
Gap for N r = 2
Conv ZF-LE
NA
3.2
Conv ZF-DFE
2.6
1.1
Conv MMSE-LE
4.2
2.0
Conv MMSE-DFE
1.7
0.8
WL ZF-LE
3.8
1.4
WL ZF-DFE
1.17
0.6
WL MMSE-LE
2.55
1.0
WL MMSE-DFE
1.05
0.5