Practical multiple-input-multiple-output (MIMO) systems depend on a
predefined set of precoders to provide spatial multiplexing gain. This
limitation on the flexibility of the precoders affects the overall performance.
Here, we propose a transmission scheme that can reduce the effect of mismatch
between users' channels and precoders. The scheme uses the channel knowledge to
generate an artificial signal, which realigns the predefined precoder to the
actual channel. Moreover, the scheme can provide an additional level of secrecy
for the communication link. The performance of the proposed scheme is evaluated
using bit-error rate (BER), error vector magnitude (EVM), and secrecy capacity.
The results show a significant improvement for the legitimate user, along with
a degradation for the eavesdropper.Comment: 4 pages, 5 figures. Accepted for publication in IEEE Communications
Letter
