  Channel polarization is a method of constructing capacity achieving codes for
symmetric binary-input discrete memoryless channels (B-DMCs) [1]. In the
original paper, the construction complexity is exponential in the blocklength.
In this paper, a new construction method for arbitrary symmetric binary
memoryless channel (B-MC) with linear complexity in the blocklength is
proposed. Furthermore, new upper and lower bounds of the block error
probability of polar codes are derived for the BEC and the arbitrary symmetric
B-MC, respectively.
