PERFORMANCE ANALYSIS FOR THE RECEIVER WITH ISI

In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and the weight profile function of the TC-AM,the bit error probability for both cases is evaluated in the sense of maximum likelihood decoding.The numerical result is given.

Blind Equalization Algorithm Based on MCMA and DSE-CMA

A new blind equalization algorithm based on the modified constant modulus algorithm （MCMA） and dithered signederror constant modulus algorithm （DSE-CMA） is proposed. This dithered signed-error MCMA （DSE-MCMA） can not only reduce the computational complexity, but also recover the phase rotation in the complex channel. Simulation results have verified the analysis and indicated the good property of DSE-MCMA.

TURBO AIDED CYCLIC PREFIX RECONSTRUCTION FOR CODED SINGLE-CARRIER SYSTEMS WITH FREQUENCY-DOMAIN EQUALIZATION (SC-FDE)

In this paper, a Turbo aided Cyclic Prefix (CP) reconstruction scheme, termed Turbo- CPR, is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient CP in the transmitter. In Turbo-CPR, the decoder output is incorporated in the process of equalization, i.e. Turbo equalizer is employed. It is shown in the simulation results that Turbo-CPR not only recovers the performance loss due to insufficiency of CP, but also provides extra gains over the lower bound of performance for conventional CP reconstruction schemes.

EFFICIENT CYCLIC PREFIX RECONSTRUCTION USING DECISION FEEDBACK FILTER FOR CODED SINGLE-CARRIER SYSTEMS WITH FREQUENCY-DOMAIN EQUALIZATION (SC-FDE)

In this paper, an efficient Cyclic Prefix （CP） reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization （SC-FDE） that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol Interference （ISI） in the equalized signal, the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error P^te （BER） performance of SC-FDE systems. In addition, the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that, when the Signal-to-Noise Ratio （SNR） exceeds a certain threshold, the proposed scheme can achieve the low bound of performance for the existing methods. Moreover, by increasing the number of iteration or through optimization, the low bound can be outperformed.

An Improved Cancellation of Nonlinear Intersymbolinter ference for Voiceband Data Transmission

in this paper ,an imprcoed nonltnear cancellation techn,que is proposed for ,wnioving nonlin-ear intersyde interference for voicel,and data lransmiss,on over dtspersive no,ilinear channels. A newstrecture 'cancellation first ,match and egualization later' is adopled in lhe ,wceiver. A fractionally-spaced equalizer (FSE)behind the nonlinear canceller can perform the functions of both a maitched fil-ter and a linear equalizer,and maximize the oulput signal to noise ralio . so that a perforniance im-provement of 2～ 3 dB is obtained compared with Biglteri's system￣[5].The ftrst order Volterra kernelmeasurement and adaptive recursive algorithms are used for the nonlinear channel eslimulor whichadaptively follws parameters of dispersive nonlinear channels. This approach allews a simple. and ef-fective implementalton ,as less computations are required. Simulation results for 9. 6 kbil/s data trans-mission over dispersive nonlinear channels show thal the nonlinear cancellalion proposed in this papercan reduce the probalelity of btt error by three orders of magnitude for the 16 QAM syuem.

On Timing Offset Estimation of OFDM

In this paper, a new timing offset estimation method for Orthogonal FrequencyDivision Multiplexing ( OFDM) systems are presented. Upon the receipt of just one trainingsequence, this presence of a signal and the start of the frame can be detected. The performances ofthe timing estimator in additive white Gaussian noise and the mo bile multipath channel areevaluated by simulation . The results delivered by this algorithm are compared with thosedelivered by Schmidl and Cox.

Mitigation of signal quality degradation induced by PMD using synchronous modulation

In-line synchronous modulation as a way of mitigating the signal quality degradation induced by polarization mode dispersion (PMD) was experimentally studied using 10-Gb/s return to zero signal. Bit error rate of the degraded signal and the synchronously modulated signal under the differential group delay (DGD) values of 10, 20, 34, and 70 ps was measured and compared. The experimental results showed that in-line synchronous modulation is useful to mitigate the signal quality degeneration induced by PMD. 1-dB power penalty reduction was obtained even when the PMD was as high as 70% of the bit interval. The limitation of method is also discussed.

Bi-iterative least squares algorithms for blind channel identification and equalization with second-order statistics

We present an adaptive algorithm for blind identification and equalization of single-input multiple-output （SIMO） FIR channels with second-order statistics. We first reformulate the blind channel identification problem into a low-rank matrix approximation solution based on the QR decomposition of the received data matrix. Then, a fast recursive algorithm is developed based on the bi-iterative least squares （Bi-LS） subspace tracking method. The new algorithm requires only a computational complexity of O（md2） at each iteration, or even as low as O（md） if only equalization is necessary, where m is the dimension of the received data vector （or the row rank of channel matrix） and d is the dimension of the signal subspace （or the column rank of channel matrix）. To overcome the shortcoming of the back substitution, an inverse QR iteration algorithm for subspace tracking and channel equalization is also developed. The inverse QR iteration algorithm is well suited for the parallel implementation in the systolic array. Simulation results are presented to illustrate the effectiveness of the proposed algorithms for the channel identification and equalization.