sentences:  If the spatial subchannels are sufficiently uncorrelated from each other, the probability that the receiver(s) will obtain linearly independent combinations (and therefore obtain innovative information) approaches 1.Although random linear network coding has excellent throughput performance, if a receiver obtains an insufficient number of packets, it is extremely unlikely that it can recover any of the original packets.This can be addressed by sending additional random linear combinations (such as by increasing the rank of the MIMO channel matrix or retransmitting at a later time that is greater than the channel coherence time) until the receiver obtains a sufficient number of coded packets to permit decoding.