  In conventional secure precise wireless transmission (SPWT), fully digital
beamforming (FDB) has a high secrecy performance in transmit antenna system,
but results in a huge RF-chain circuit budget for medium-scale and large-scale
systems. To reduce the complexity, this letter considers a hybrid digital and
analog (HDA) structure with random frequency mapped into the RF-chains to
achieve SPWT. Then, a hybrid SPWT scheme based on maximizing
signal-to-leakage-and-noise ratio (SLNR) and
artificial-noise-to-leakage-and-noise ratio (ANLNR) (M-SLNR-ANLNR) is proposed.
Compared to the FDB scheme, the proposed scheme reduces the circuit budget with
low computational complexity and comparable secrecy performance.
