  Cell-free massive MIMO provides ubiquitous connectivity for multiple users,
and implementation using radio stripes is very efficient. Compared with
collocated massive MIMO, the major cost includes fronthaul overheads and AP
hardware. Maximum ratio combination (MRC) achieves a low fronthaul loading and
low-cost AP, but the performance is bad. This letter proposes to implement a
quasi-LMMSE (Q-LMMSE) processing using MRC fronthaul design. Q-LMMSE is derived
from a standard LMMSE, which gains interference information from MRC signal via
singular value decomposition. Simulation results show that the proposed Q-LMMSE
increases the spectral efficiency by several times using same MRC fronthaul.
