A millimeter-wave transmitter architecture that inserts radio-frequency switch networks at both ends of the phase-shifter network, so that RF chains, antenna sub-arrays and phase shifters are connected only as the number of data streams demands, and that treats the resolution of each digital-to-analog converter as an optimization variable rather than a fixed hardware choice. Energy efficiency is defined as spectral efficiency divided by total transceiver power, where the power model sums per-bit DAC power, RF chain, switch, phase shifter, antenna element and baseband terms together with power-amplifier efficiency. The resulting nonconvex joint design of digital precoder, switch selection, analog phase-shifter matrix and DAC resolution vector is solved by block coordinate descent: the resolution vector is fixed while alternating minimization fits the precoding matrices, then the precoding matrices are fixed while the resolution vector is searched, subject to a floor on spectral efficiency relative to a fully-connected baseline. The design point it teaches is that deliberately spending a bounded amount of spectral efficiency (about 17 percent versus a fully-connected array) buys a large reduction in hardware power, and that the resulting scheme stays robust when channel state information is imperfect.
This Chinese-language engineering paper (published in Mobile Communications, vol. 48, no. 12, pp. 86-96, December 2024; 21 pages, 8 figures) proposes a low-power hybrid beamforming architecture for m…