This paper first introduces the classic Tomlinson-Harashima Precoding(THP),then makes analysis respectively on the trellis preceding and nonlinear transmit zero-forcing based on THP,including their features,and point out that the nonlinear pre-processing technology is the tradeoff of performance and complexity and has potentialities for the downlinks.

The design of Hairpin microstrip band-pass filter with transmission zeros;

Through the research on the design of the general Chebyshev filters,a comprehensive method of calculating transmission zeros is brought forward according to the given targets.

Determination of transmission zeros is important in synthesis of cross-coupled filter.

Design and fabrication of LTCC bandpass filter with two-transmission zeros

Based on the equivalent circuit model of bandpass filter,the physical models are constructed in Ansoft-HFSS with the introduction of the low resistance of the two transmission zero.

The equivalent-circuit values of the cell model are extracted by the curve-fitting technology,and then the transmission zero location,dispersive relation,refraction index and transmission characteristic of the cascaded structures are derived.

Based on two low complexity algorithms BID(Bi-Directional ZF) and PIC(Parallel Interference Cancellation),we propose a novel combination detection algorithm BID-PIC of Zero-Forcing BLAST(Bell Laboratories Layered Space Time).

Among this,Zero-Forcing(ZF),Minimum Mean-Squared Error(MMSE) and Maximum Likelihood(ML) are three commonly used detection algorithms.

Con- ventional zero- force channel estimation(ZF- CE) degrades the BER performance, since the frequency spectrum of the pilot sequence is not constant in envelope.