The authors propose a novel use of complete complementary (CC) sequences for increased spectral efficiency in a multiple-input-multiple-output (MIMO) code division multiple access (CDMA) system. The new method overcomes many of the problems and limitations persistent in single-input-single-output (SISO) and proves that under the proposed MIMO CC-CDMA system, the capacity for the number of supported users increases linearly by the number of transmitters. The paper also shows that the MIMO CC-CDMA system demonstrates a superior performance over those using traditional Walsh spreading sequences (Walsh-CDMA). Results include the bit error rate comparison for CC-CDMA frequency selective fading channels and that of the Walsh-CDMA under flat fading channels.
In this paper, we present a Multiple-InputMultiple-Output (MIMO) Code-Division-Multiple-Access (CDMA) communication system based on Complete Complementary (CC) codes (CC-CDMA) in a timedispersive (i.e. frequency-selective fading) channel. This system utilizes a novel combination, which consists of orthogonal CC codes for data spreading and a suitably designed Multi-User-Detector (MUD) algoaithm, in order to enhance the current 3rd Generation (3G) mobile systems. The simulation results for the CC-CDMA system, obtained in a frequency-selective fading channel, reveal significant improvement in Bit-Error-Rate (BER) performance, and consequently the achieved High Data Rates (HDR) compared with a conventional Walsh codes based MIMO CDMA (Walsh-CDMA) system.
This paper presents the design of two-stage beam alignment methods employing a hybrid analog-digital antenna array and exploiting the beam pattern in a point-to-point millimeter-wave (mmWave) radio for mmWave massive multipleinput multiple-output systems. We investigate an antenna deactivating approach that generates wider beams at the coarse alignment stage and exploit the theoretical beam pattern at the fine alignment stage. Our numerical results show that the proposed two-stage methods can achieve a better beam alignment than existing exhaustive methods and avail measurements/complexity reductions by tuning key parameters governing the alignment performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.