The derivation and the performance analysis of a kind of high-rate low density parity check （LDPC）codes algorithm are proposed to the application of impulse radio ultra-wideband (IR-UWB) communication system. The PEG algorithm is combined with block quasi-cyclic manner to construct the parity check matrix and the two different algorithms performance are compared by using the matrix I and matrix Q as the sub-block cyclic matrix. The performance analysis is conducted with bit-error curve from Matlab simulation. Moreover, the minimum sum (MS) decoding algorithm based on a variable factor of the design is proposed and the final low complexity low density parity-check code (LDPC) decoder incurs only about 3.2dB signal-to-noise ratio (SNR) loss with the error rate of 10-6 bit in standard UWB fading channels.