  The benefit of multi-antenna receivers is investigated in wireless ad hoc
networks, and the main finding is that network throughput can be made to scale
linearly with the number of receive antennas nR even if each transmitting node
uses only a single antenna. This is in contrast to a large body of prior work
in single-user, multiuser, and ad hoc wireless networks that have shown linear
scaling is achievable when multiple receive and transmit antennas (i.e., MIMO
transmission) are employed, but that throughput increases logarithmically or
sublinearly with nR when only a single transmit antenna (i.e., SIMO
transmission) is used. The linear gain is achieved by using the receive degrees
of freedom to simultaneously suppress interference and increase the power of
the desired signal, and exploiting the subsequent performance benefit to
increase the density of simultaneous transmissions instead of the transmission
rate. This result is proven in the transmission capacity framework, which
presumes single-hop transmissions in the presence of randomly located
interferers, but it is also illustrated that the result holds under several
relaxations of the model, including imperfect channel knowledge, multihop
transmission, and regular networks (i.e., interferers are deterministically
located on grids).
