In recent times, there has been growing interests in integration of voice, data and video traffic in wireless communication networks. With these growing interests, WCDMA has immerged as an attractive access technique....In recent times, there has been growing interests in integration of voice, data and video traffic in wireless communication networks. With these growing interests, WCDMA has immerged as an attractive access technique. The performance of WCDMA system is deteriorated in presence of multipath fading environment. The paper presents space-time coded minimum mean square error (MMSE) Decision Feedback Equalizer (DFE) for wideband code division multiple access (WCDMA) in a frequency selective channel. The filter coefficients in MMSE DFE are optimized to suppress noise, intersymbol interference (ISI), and multiple access interference (MAI) with reasonable system complexity. For the above structure, we have presented the estimation of BER for a MMSE DFE using computer simulation experiments. The simulation includes the effects of additive white Gaussian noise, multipath fading and multiple access interference (MAI). Furthermore, the performance is compared with standard linear equalizer (LE) and RAKE receiver. Numerical and simulation results show that the MMSE DFE exhibits significant performance improvement over the standard linear equalizer (LE) and RAKE receiver.展开更多
High spectral efficiency is essential in design of multimedia communication systems such as L-band mobile in addition to various requirements of transmission quality.Time-interleaved A/D converter(TI-ADC)is an effecti...High spectral efficiency is essential in design of multimedia communication systems such as L-band mobile in addition to various requirements of transmission quality.Time-interleaved A/D converter(TI-ADC)is an effective candidate to implement wide-band ADC with relatively slow circuits accounting for digital spectrum management.However,practical performance of TI-ADC is largely limited because of mismatches between different channels originated from manufacturing process variations.In this paper,a blind adaptive method is proposed to correct gain mismatch errors in TI-ADC,and it is verified through simulations on a two-channel TI-ADC.In proposed method,gain mismatch error is estimated and corrected in an adaptive scheme.Proposed compensated TI-ADC architecture is structurally very simple and hence suitable for realization in integrated circuits.Besides,proposed digital compensation algorithm not only is computationally efficient but also provides an improvement of 32.7 dB in the performance of two-channel TI-ADC.展开更多
在WCDMA中,TFCI(Transport Format Combination Indicator,传输格式组合标识)非常重要。WCDMA中TFCI的编码有两种方案,一种是在正常模式下,另一种是在分裂模式下。已有的穷举法译码方法具有效率低的缺陷,该文提出利用反哈德马德变换进...在WCDMA中,TFCI(Transport Format Combination Indicator,传输格式组合标识)非常重要。WCDMA中TFCI的编码有两种方案,一种是在正常模式下,另一种是在分裂模式下。已有的穷举法译码方法具有效率低的缺陷,该文提出利用反哈德马德变换进行高效TFCI译码的方案。仿真表明了该译码方案的有效性。展开更多
文摘In recent times, there has been growing interests in integration of voice, data and video traffic in wireless communication networks. With these growing interests, WCDMA has immerged as an attractive access technique. The performance of WCDMA system is deteriorated in presence of multipath fading environment. The paper presents space-time coded minimum mean square error (MMSE) Decision Feedback Equalizer (DFE) for wideband code division multiple access (WCDMA) in a frequency selective channel. The filter coefficients in MMSE DFE are optimized to suppress noise, intersymbol interference (ISI), and multiple access interference (MAI) with reasonable system complexity. For the above structure, we have presented the estimation of BER for a MMSE DFE using computer simulation experiments. The simulation includes the effects of additive white Gaussian noise, multipath fading and multiple access interference (MAI). Furthermore, the performance is compared with standard linear equalizer (LE) and RAKE receiver. Numerical and simulation results show that the MMSE DFE exhibits significant performance improvement over the standard linear equalizer (LE) and RAKE receiver.
基金Iran’s Telecommunication Research Center(ITRC)(No.500/3653)
文摘High spectral efficiency is essential in design of multimedia communication systems such as L-band mobile in addition to various requirements of transmission quality.Time-interleaved A/D converter(TI-ADC)is an effective candidate to implement wide-band ADC with relatively slow circuits accounting for digital spectrum management.However,practical performance of TI-ADC is largely limited because of mismatches between different channels originated from manufacturing process variations.In this paper,a blind adaptive method is proposed to correct gain mismatch errors in TI-ADC,and it is verified through simulations on a two-channel TI-ADC.In proposed method,gain mismatch error is estimated and corrected in an adaptive scheme.Proposed compensated TI-ADC architecture is structurally very simple and hence suitable for realization in integrated circuits.Besides,proposed digital compensation algorithm not only is computationally efficient but also provides an improvement of 32.7 dB in the performance of two-channel TI-ADC.
文摘在WCDMA中,TFCI(Transport Format Combination Indicator,传输格式组合标识)非常重要。WCDMA中TFCI的编码有两种方案,一种是在正常模式下,另一种是在分裂模式下。已有的穷举法译码方法具有效率低的缺陷,该文提出利用反哈德马德变换进行高效TFCI译码的方案。仿真表明了该译码方案的有效性。
