Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs, and reduces the required transmission bandwidth b...Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs, and reduces the required transmission bandwidth by up to 80%. In addition you get improved voice quality and better QoS.展开更多
Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs,
Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs,
针对多径环境下异步长短码直扩码分多址信号(long and short code direct sequence code division multiple access,LSC-DS-CDMA)伪码估计难的问题,提出一种基于张量分解和联合估计的伪码估计方法,采用重叠窗对接收信号进行分段并构建...针对多径环境下异步长短码直扩码分多址信号(long and short code direct sequence code division multiple access,LSC-DS-CDMA)伪码估计难的问题,提出一种基于张量分解和联合估计的伪码估计方法,采用重叠窗对接收信号进行分段并构建张量模型。为改善传统线性步长搜索算法结合梯度下降的方法分解因子矩阵收敛较慢的问题,提出改进的线性步长搜索算法,结合使用动量梯度下降法对各子张量进行Tucker分解得到各因子矩阵,所需的迭代次数大大减少;利用接收增益矩阵和移位相乘解决复合码的排序模糊和幅度模糊问题;利用最大似然准则联合估计复合码和多径信道后,使用梅西算法和相关运算估计每个用户的长码和短码。仿真结果表明,该方法能够有效估计多径异步LSC-DS-CDMA信号的伪码。展开更多
文摘Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs, and reduces the required transmission bandwidth by up to 80%. In addition you get improved voice quality and better QoS.
文摘Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs,
文摘Our new All-IP CDMA2000 solution is the first IOS V5.0-based system to be launched commercially. This evolutionary system gives you up to 30% savings on vocoder costs,
文摘针对多径环境下异步长短码直扩码分多址信号(long and short code direct sequence code division multiple access,LSC-DS-CDMA)伪码估计难的问题,提出一种基于张量分解和联合估计的伪码估计方法,采用重叠窗对接收信号进行分段并构建张量模型。为改善传统线性步长搜索算法结合梯度下降的方法分解因子矩阵收敛较慢的问题,提出改进的线性步长搜索算法,结合使用动量梯度下降法对各子张量进行Tucker分解得到各因子矩阵,所需的迭代次数大大减少;利用接收增益矩阵和移位相乘解决复合码的排序模糊和幅度模糊问题;利用最大似然准则联合估计复合码和多径信道后,使用梅西算法和相关运算估计每个用户的长码和短码。仿真结果表明,该方法能够有效估计多径异步LSC-DS-CDMA信号的伪码。
