Deng Ke,Yin Qinye,Zhang Yiwen,Luo Ming
(School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an ¡¡710049,China)
Abstract:Focusing on the problem that conventional space-time coding systems resolve the channel state information by exploiting training sequences and lead to consumption of bandwidth resource,a blind vector channel impulse response (VCIR) estimation algorithm was proposed, which is suitable for the multi-carrier code division multiple access (MC-CDMA) systems based on the space-time block coding (STBC) with multiple receiving antennae at the base station. Unlike other blind VCIR estimation algorithms, the proposed algorithm can implement the blind estimation when each user only employs one spread code. Therefore, the maximum number of active users can not be decreased. Successively, a corresponding space-time multiuser detector was constructed according to the estimated VCIR for the base station with multiple receiving antennae. When applying STBC to the user side, the transmit diversity can be utilized better and the transmit rate is increased. Computer simulation results show that the number of active users not only can be reached to the upper bound by the detector, but also the bit error rate can be decreased by 40% with one receiving antenna in the case that the active users are of 14 and the signal to noise ratio is the same.
Keywords:multicarrier code-division multiple access;space-time block coding;vector channel impulseresponse;multiuser detection