In the transmitting, beamforming, and receiving combing （TBRC） MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the...In the transmitting, beamforming, and receiving combing （TBRC） MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization （USVQ） codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean （USK） codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.展开更多
This paper presents analytical expressions for the multiple-input multiple-output （MIMO） channel capacity in frequency-flat Rayleigh fading environments. An exact analytical expression is given for the ergodic capac...This paper presents analytical expressions for the multiple-input multiple-output （MIMO） channel capacity in frequency-flat Rayleigh fading environments. An exact analytical expression is given for the ergodic capacity for single-input multiple-output （SIMO） channels. The analysis shows that the SIMO channel capacity can be approximated by a Gaussian random variable and that the MIMO channel capacity can be approximated as the sum of multiple SIMO capacities. The SIMO channel results are used to derive approximate closed-form expressions for the MIMO channel ergodic capacity and the complementary cumulative distribution function （CCDF） of the MIMO channel capacity （outage capacity）. Simulations show that these theoretical results are good approximations for MIMO systems with an arbitrary number of transmit or receive antennas. Moreover, these analytical expressions are relatively simple which makes them very useful for practical computations.展开更多
针对球译码检测算法的搜索半径影响着其算法复杂度的问题,提出一种改进算法。改进算法对球译码检测算法的搜索半径乘上一个常量压缩因子,且在每层搜索中削减噪声因子的影响。通过缩减搜索球半径、缩小搜索范围实现算法复杂度的降低。仿...针对球译码检测算法的搜索半径影响着其算法复杂度的问题,提出一种改进算法。改进算法对球译码检测算法的搜索半径乘上一个常量压缩因子,且在每层搜索中削减噪声因子的影响。通过缩减搜索球半径、缩小搜索范围实现算法复杂度的降低。仿真结果显示:在信噪比低于10 d B时,改进算法比传统球译码检测算法计算复杂度平均降低18%左右,同时误码性能损失较小。展开更多
基金the National Natural Science Foundation of China（60702051）the Hi-Tech Research and Development Program of China（2006AAQ IZ260）and Huawei company.
文摘In the transmitting, beamforming, and receiving combing （TBRC） MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization （USVQ） codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean （USK） codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.
文摘This paper presents analytical expressions for the multiple-input multiple-output （MIMO） channel capacity in frequency-flat Rayleigh fading environments. An exact analytical expression is given for the ergodic capacity for single-input multiple-output （SIMO） channels. The analysis shows that the SIMO channel capacity can be approximated by a Gaussian random variable and that the MIMO channel capacity can be approximated as the sum of multiple SIMO capacities. The SIMO channel results are used to derive approximate closed-form expressions for the MIMO channel ergodic capacity and the complementary cumulative distribution function （CCDF） of the MIMO channel capacity （outage capacity）. Simulations show that these theoretical results are good approximations for MIMO systems with an arbitrary number of transmit or receive antennas. Moreover, these analytical expressions are relatively simple which makes them very useful for practical computations.
文摘针对球译码检测算法的搜索半径影响着其算法复杂度的问题,提出一种改进算法。改进算法对球译码检测算法的搜索半径乘上一个常量压缩因子,且在每层搜索中削减噪声因子的影响。通过缩减搜索球半径、缩小搜索范围实现算法复杂度的降低。仿真结果显示:在信噪比低于10 d B时,改进算法比传统球译码检测算法计算复杂度平均降低18%左右,同时误码性能损失较小。
