To evaluate the ranging performance of impulse radio ultra wideband （IR-UWB） signals, an experiment is performed in a typical indoor environment. In order to mitigate the ranging error caused by theoretical algorith...To evaluate the ranging performance of impulse radio ultra wideband （IR-UWB） signals, an experiment is performed in a typical indoor environment. In order to mitigate the ranging error caused by theoretical algorithm and practical circuits, one way-time difference of the arrival （OW-TDOA） ranging method and corresponding approaches are proposed and carried out according to the structure of UWB transceivers. Generalized maximum likelihood （GML） estimator based on energy detection is applied for the time of arrival estimation. The obtained results show that this UWB ranging system can achieve a relative high ranging accuracy in a multipath environment （e.g. about 5 cm at ranges up to 6 m）, which is practical and meaningful for many sensor applications.展开更多
该文提出脉冲超宽带(Impulse Radio Ultra WideBand,IR-UWB)系统中一种基于改进传播算子算法(Propagator Method,PM)的到达时间(Time-Of-Arrival,TOA)和波达方向(Direction-Of-Arrival,DOA)联合估计方法。首先直接对接收信号的频域形式...该文提出脉冲超宽带(Impulse Radio Ultra WideBand,IR-UWB)系统中一种基于改进传播算子算法(Propagator Method,PM)的到达时间(Time-Of-Arrival,TOA)和波达方向(Direction-Of-Arrival,DOA)联合估计方法。首先直接对接收信号的频域形式建模,然后采用改进的PM算法估计出两根天线的TOA参数,最后由两根天线的到达时间差计算出信号的DOA参数,从而达到TOA和DOA联合估计的目的。该算法无需谱峰搜索就可直接得到TOA和DOA的闭式解,且可以实现参数自动配对,大大降低了复杂度。最后给出了该算法的大量实验仿真,以及与现有算法的比较,仿真结果验证了该方法的可行性、稳健性和优越性。展开更多
传统的信号检测算法基于奈奎斯特采样定理来实现,这对于带宽极宽的超宽带(ultra-wideband,UWB)信号而言由于要求采样速率过高而很难用硬件去实现。为此,本文研究了基于压缩感知(compressive sensing,CS)的脉冲超宽带(impulse radio UWB,...传统的信号检测算法基于奈奎斯特采样定理来实现,这对于带宽极宽的超宽带(ultra-wideband,UWB)信号而言由于要求采样速率过高而很难用硬件去实现。为此,本文研究了基于压缩感知(compressive sensing,CS)的脉冲超宽带(impulse radio UWB,IR-UWB)信号检测问题,利用IR-UWB信号在时域上的稀疏特性,设计了一种基于压缩感知的IR-UWB信号检测框架,在此基础上提出了一种自适应加权正交匹配追踪检测算法。仿真结果表明,新算法不仅能够通过远少于奈奎斯特定理所要求的采样速率检测出IR-UWB信号,而且与基于匹配追踪的压缩感知检测算法相比,新算法在低信噪比的情况下对IR-UWB信号的检测效果更佳。展开更多
We theoretically analyze the channel capacity of a 5th-order Gaussian pulse-based ultra-wideband （UWB） system and experimentally demonstrate 2 Gbit/s UWB-over-fiber transmission systems incorporating wireless transm...We theoretically analyze the channel capacity of a 5th-order Gaussian pulse-based ultra-wideband （UWB） system and experimentally demonstrate 2 Gbit/s UWB-over-fiber transmission systems incorporating wireless transmission. Both electrical and photonic UWB pulse generation methods are employed and its performance is compared. By utilizing optimum UWB pulse design and employing a digital signal processing （DSP） receiver, a bit-error-rate above the forward error correction （FEC） limit for 8 meters of wireless＇emis- sion is obtained in our photonic generation UWB system. A noticeable increase in the channel capacity is achieved compared to previously reported results.展开更多
This paper treats the digital design of a probabilistic energy equalizer for impulse radio (IR) UWB receiver in high data rate (100Mbps). The aim of this study is to bypass certain complex mathematical function as a c...This paper treats the digital design of a probabilistic energy equalizer for impulse radio (IR) UWB receiver in high data rate (100Mbps). The aim of this study is to bypass certain complex mathematical function as a chi-squared distribution and reduce the computational complexity of the equalizer for a low cost hardware implementation. As in Sub-MAP algorithm, the max* operation is investigated for complexity reduction and tested by computer simulation with fixed point data types under 802.15.3a channel models. The obtained re-sults prove that the complexity reduction involves a very slight algorithm deterioration and still meet the low-cost constraint of the implementation.展开更多
Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential...Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential-detector is proposed for impulse radio ultra wideband (IR-UWB) communication systems. The system employs bit-level differential phase shift keying (DPSK) combined with code division (CD) for IR-UWB signals to support multiple-access (MA). It is analyzed under additive white Gaussian noise (AWGN) corrupted by multiple-access interference (MAI) channel. Its BER performance is compared against a reference coherent receiver using Monte-Carlo simulation method. A closed form expression for its average probability of error is derived analytically. Simulation results and theoretical analysis confirm the applicability of the proposed differential-detector for IR-UWB communication systems.展开更多
基金supported by the Key Program of the National Natural Science Foundation of China(60432040)the Program of National Natural Science Foundation of China(60702034).
文摘To evaluate the ranging performance of impulse radio ultra wideband （IR-UWB） signals, an experiment is performed in a typical indoor environment. In order to mitigate the ranging error caused by theoretical algorithm and practical circuits, one way-time difference of the arrival （OW-TDOA） ranging method and corresponding approaches are proposed and carried out according to the structure of UWB transceivers. Generalized maximum likelihood （GML） estimator based on energy detection is applied for the time of arrival estimation. The obtained results show that this UWB ranging system can achieve a relative high ranging accuracy in a multipath environment （e.g. about 5 cm at ranges up to 6 m）, which is practical and meaningful for many sensor applications.
文摘该文提出脉冲超宽带(Impulse Radio Ultra WideBand,IR-UWB)系统中一种基于改进传播算子算法(Propagator Method,PM)的到达时间(Time-Of-Arrival,TOA)和波达方向(Direction-Of-Arrival,DOA)联合估计方法。首先直接对接收信号的频域形式建模,然后采用改进的PM算法估计出两根天线的TOA参数,最后由两根天线的到达时间差计算出信号的DOA参数,从而达到TOA和DOA联合估计的目的。该算法无需谱峰搜索就可直接得到TOA和DOA的闭式解,且可以实现参数自动配对,大大降低了复杂度。最后给出了该算法的大量实验仿真,以及与现有算法的比较,仿真结果验证了该方法的可行性、稳健性和优越性。
文摘传统的信号检测算法基于奈奎斯特采样定理来实现,这对于带宽极宽的超宽带(ultra-wideband,UWB)信号而言由于要求采样速率过高而很难用硬件去实现。为此,本文研究了基于压缩感知(compressive sensing,CS)的脉冲超宽带(impulse radio UWB,IR-UWB)信号检测问题,利用IR-UWB信号在时域上的稀疏特性,设计了一种基于压缩感知的IR-UWB信号检测框架,在此基础上提出了一种自适应加权正交匹配追踪检测算法。仿真结果表明,新算法不仅能够通过远少于奈奎斯特定理所要求的采样速率检测出IR-UWB信号,而且与基于匹配追踪的压缩感知检测算法相比,新算法在低信噪比的情况下对IR-UWB信号的检测效果更佳。
基金supported by a Marie Curie International Incoming Fellow-ship and ICT-ALPHA Project within the 7th European Community Framework Programme
文摘We theoretically analyze the channel capacity of a 5th-order Gaussian pulse-based ultra-wideband （UWB） system and experimentally demonstrate 2 Gbit/s UWB-over-fiber transmission systems incorporating wireless transmission. Both electrical and photonic UWB pulse generation methods are employed and its performance is compared. By utilizing optimum UWB pulse design and employing a digital signal processing （DSP） receiver, a bit-error-rate above the forward error correction （FEC） limit for 8 meters of wireless＇emis- sion is obtained in our photonic generation UWB system. A noticeable increase in the channel capacity is achieved compared to previously reported results.
文摘This paper treats the digital design of a probabilistic energy equalizer for impulse radio (IR) UWB receiver in high data rate (100Mbps). The aim of this study is to bypass certain complex mathematical function as a chi-squared distribution and reduce the computational complexity of the equalizer for a low cost hardware implementation. As in Sub-MAP algorithm, the max* operation is investigated for complexity reduction and tested by computer simulation with fixed point data types under 802.15.3a channel models. The obtained re-sults prove that the complexity reduction involves a very slight algorithm deterioration and still meet the low-cost constraint of the implementation.
文摘Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential-detector is proposed for impulse radio ultra wideband (IR-UWB) communication systems. The system employs bit-level differential phase shift keying (DPSK) combined with code division (CD) for IR-UWB signals to support multiple-access (MA). It is analyzed under additive white Gaussian noise (AWGN) corrupted by multiple-access interference (MAI) channel. Its BER performance is compared against a reference coherent receiver using Monte-Carlo simulation method. A closed form expression for its average probability of error is derived analytically. Simulation results and theoretical analysis confirm the applicability of the proposed differential-detector for IR-UWB communication systems.
文摘针对传统能量检测算法在强窄带干扰存在时到达时间(time of arrive, TOA)估计精度不高的问题,采用了一种结合平方律器件和带通滤波器的平方滤波技术来缓和窄带干扰对TOA估计的影响,并分别在IEEE 802.15.4a CM3视距信道和CM4非视距信道下与TOA估计方法相结合得到系统的估计结果.理论分析和仿真结果表明,存在窄带干扰时,采用了平方滤波技术的能量检测方法比传统的能量检测方法具有更高的TOA估计精度.在视距环境中应用平方滤波技术后,TOA估计精度可从2.8 ns提升至0.5 ns,而非视距环境中可从6 ns提升至1 ns.
