Adaptive Semi-blind Channel Estimation for ST-BC MIMO-CDMA Systems with Hybrid User Signature

[[abstract]]we extend our previous work to present a new semi-blind transceiver for the direct-sequence code division multiple access (DS-CDMA) system that uses multiple transmit and receive antennas (MIMO) system, equipped with space-time block code (ST-BC). In the transmitter we design a new hybrid augmented user signature (AUS) that composes of the desired user signatures and the prefix/postfix zero-padding sequences with respect to individual transmit-antennas. The hybrid AUS is devised to resolve the phase ambiguity problem which occurs in all blind receivers. At the receiver we propose a Capon-like semiblind two-branch filter bank receiver, based on the linearly constrained constant modulus (LCCM) criterion, followed by the AUS-assisted semi-blind channel estimation and power method for block symbol recovery. This enables us to partially alleviate the effects of inter-block interference (IBI) and the multiple access interference (MAI). In the ST-BC MIMO-CDMA receiver with two-branch filterbank, we build on the generalized sidelobe canceller (GSC) structure with the RLS for implementing the adaptive semi-blind LCCM receiver. Via intense simulations it reveals that our proposed new transceiver has robust performance against the user’s acquisition inaccuracies comparing with current vailable algorithms and to resolve the phase ambiguity problem.[[sponsorship]]IEEE Circuits and Systems Society; IEICE ESS (Institute of Electronics, Information and Communication Engineers - Engineering Sciences Society); Tokyo City University; International Exchange Program of National Institute of Information and Communications Technology (NICT); Support Center for Advanced Telecommunications Technology Research, Foundation; Tateisi Science and Technology Foundation[[incitationindex]]EI[[conferencetype]]國際[[conferencedate]]20131112~20131115[[booktype]]電子版[[iscallforpapers]]Y[[conferencelocation]]Okinawa, Japa

Single-carrier FDMA or cyclic-prefix CDMA with optimized spreading sequences

To meet the data rate and quality-of-service requirements of the future cellular systems, new air interfaces are currently under development. In this paper, we compare two air interfaces of particular interest for the uplink: (1) cyclic-prefix code-division multiple access (CP-CDMA), which has been proposed in the literature as an evolution of direct-sequence code-division multiple access (DS-CDMA) because it enables the low-complexity equalization of the multipath channel in the frequency domain, and (2) single-carrier frequency-division multiple access (SC-FDMA), which has recently been proposed in the long-term evolution of the Third-Generation Partnership Project (3GPP) standard because it enables the easy separation of users in the frequency domain. We analytically demonstrate that SC-FDMA is a special case of CP-CDMA, in which the CDMA codes have been optimized to minimize symbol estimation mean square error under a constraint of received power. Numerical results confirm that SC-FDMA significantly outperforms CP-CDMA at high user loads.info:eu-repo/semantics/publishe