  Problems in realization of silicon-based solid-state NMR quantum computer
with ensemble addressing to qubits are considered. It is presented the
extension of Kane's scheme to ensemble approach version with strip gates. For
the initialization of nuclear quantum states it is proposed to use the
solid-state effect in ENDOR technique whereby the nuclear spins can be
practically fully polarized or, that is the same, indirect cooled to the spin
temperature less than ~ 1 mK. It is suggested the possible planar silicon
topology of such ensemble quantum computer and shown that the measurement with
standard NMR methods signal of L ~ 10^3 qubit system may be achieved for a
number of ensemble components N >= 10^5. As another variant of ensemble silicon
quantum computer the gateless architecture of cellular-automaton is also
considered. The decoherence of quantum states in the ensemble quantum computers
and ways of its suppression is also discussed.
