THz wireless communications offer very high data rates but tend to be power hungry. This paper demonstrates a technique for drastically reducing receiver-side power consumption for near-field links using 300-GHz CMOS transmitter (TX) and receiver (RX). Since a significant part of RX-side power consumption is accounted for by THz LO signal generation used for downconversion, the RX obviates the need by letting the TX send out not only a signal sideband but also an LO signal, which is a by-product of upconversion and usually is suppressed. The RX then performs self-heterodyne mixing for signal downconversion. The TX and RX can operate in this low-power "full-(pseudo-)carrier transmission/reception mode" and in the ordinary "suppressed-(pseudo-)carrier TX/RX mode." In the low-power mode, the RX achieved a data rate of 17.64 Gb/s with 64-QAM over 1 cm at 6 mW dc power consumption at 295.92 GHz. The dc power consumption in normal mode was 645 mW at comparable data rates.