  Integer forcing is an alternative approach to conventional linear receivers
for multiple-antenna systems. In an integer-forcing receiver, integer linear
combinations of messages are extracted from the received matrix before each
individual message is recovered. Recently, the integer-forcing approach was
generalized to a block fading scenario. Among the existing variations of the
scheme, the ones with the highest achievable rates have the drawback that no
efficient algorithm is known to find the best choice of integer linear
combination coefficients. In this paper, we propose several sub-optimal methods
to find these coefficients with low complexity, covering both parallel and
successive interference cancellation versions of the receiver. Simulation
results show that the proposed methods attain a performance close to optimal in
terms of achievable rates for a given outage probability. Moreover, a
low-complexity implementation using root LDPC codes is developed, showing that
the benefits of the proposed methods also carry on to practice.
