  This paper proposes new scheme for efficient rate allocation in conjunction
with reducing peak-to-average power ratio (PAPR) in orthogonal
frequency-division multiplexing (OFDM) systems. Modification of the set
partitioning in hierarchical trees (SPIHT) image coder is proposed to generate
four different groups of bit-stream relative to its significances. The
significant bits, the sign bits, the set bits and the refinement bits are
transmitted in four different groups. The proposed method for reducing the PAPR
utilizes twice the unequal error protection (UEP), using the Read-Solomon codes
(RS), in conjunction with bit-rate allocation and selective interleaving to
provide minimum PAPR. The output bit-stream from the source code (SPIHT) will
be started by the most significant types of bits (first group of bits). The
optimal unequal error protection (UEP) of the four groups is proposed based on
the channel destortion. The proposed structure provides significant improvement
in bit error rate (BER) performance. Performed computer simulations have shown
that the proposed scheme outperform the performance of most of the recent PAPR
reduction techniques in most cases. Moreover, the simulation results indicate
that the proposed scheme provides significantly better PSNR performance in
comparison to well-known robust coding schemes.
