M ∗ activate node selection: note that M nodes are distributed over transmitter cluster, where M ∗
V-MIMO technique is proposed for CSI feedback, where the receivers simultaneously transmit their CSIs to the associated transmitters, which are cooperatively decoded at the transmitter cluster.
V-MIMO is performed by the following sequential procedures: (1) local data exchange between neighboring transmitters, (2) CSI feedback from the receiver to transmitter, and (3) cooperative transmission from the transmitter cluster to the corresponding receivers.
However, previous literature showed that CSI feedback of all channel links between receiver cluster and transmitter cluster are required to realize the cooperative beamforming, which significantly degrades the spectral efficiency as the number of nodes participating in the cooperation increases.
However, in the medium value of transmission power, increasing the number of cooperation nodes does not always provide a higher spectral efficiency as it requires a large amount of bandwidth for local data exchange at the transmitter cluster.
Some HyHKs may have also arisen through duplication of a classical HK and fusion with a REC domain of a RR, as previously described [ 38, 39]; such a scenario has likely occurred for AZOLI_1645, in which the transmitter domain clusters with those of two classical HKs (YP_003448836.1 and YP_005031706.1) and the REC domain grouping with that of a RR (YP_003452077.1) (data not shown).
Therefore, the signal power gain of the transmitter-to-cluster main path is modeled as having lognormal distribution, pLn, because of the multiplicative effects of reflections and/or diffractions, while that of the local multipaths are modeled as Rayleigh distributed, pR, due to additive scattering effects.
In an effort to improve the spectral efficiency in V-MIMO systems, the optimal channel and power allocation between local and long-range transmission between transmitter and receiver clusters was proposed to minimize the outage capacity in [16].
In fact, 32 out of 49 transmitter domains were clustered into clades containing sequences of various bacteria that are not related to Azospirillum (not shown).
As code-words are transmitted from the nested clusters, the transmitter partitions its power, and in order to decode superposition-coded messages, each receiver begins by decoding and subtracting the signals intended for more-degraded receivers.
