  We study combined leptoquark (LQ) single and pair production at LHC at the
level of detector simulation. A set of kinematical cuts has been worked out to
maximize significance for combined signal events.
  It was shown that combination of signatures from LQ single and pair
production not only significantly increases the LHC reach, but also allows us
to give the correct signal interpretation. In particular, it was found that the
LHC has potential to discover LQ with a mass up to 1.2 TeV and 1.5 TeV for the
case of scalar and vector LQ, respectively, and LQ single production
contributes 30-50% to the total signal rate for LQ-l-q coupling, taken equal to
the electromagnetic coupling.
  This work is based on implementation of the most general form of scalar and
vector LQ interactions with quarks and gluons into CalcHEP/CompHEP packages.
This implementation, which authors made publicly available, was one the most
important aspects of the study.
