  A novel coding scheme for exact repair-regenerating codes is presented in
this paper. The codes proposed in this work can trade between the repair
bandwidth of nodes (number of downloaded symbols from each surviving node in a
repair process) and the required storage overhead of the system. These codes
work for general system parameters $(n,k,d)$, which are the total number of
nodes, the number of nodes suffice for data recovery, and the number of helper
nodes in a repair process, respectively. The proposed construction offers a
unified scheme to develop exact-repair regenerating codes for the entire
trade-off, including the MBR and MSR points. We conjecture that the new
storage-vs.-bandwidth trade-off achieved by the proposed codes is optimum. Some
other key features of this code include: the construction is linear; the
required field size is only $\Theta(n)$; and the code parameters and in
particular sub-packetization level is at most $(d-k+1)^k$; which is independent
of the number of the parity nodes. Moreover, the proposed repair mechanism is
\emph{helper-independent}, that is the data sent from each helper only depends
on the identity of the helper and failed nodes, but independent of the identity
of other helper nodes participating in the repair process.
