Overloaded TDD-CDMA cells with multiuser transmission

Abstract

The number of supportable users in the TDD- [I]. All MUT methods have the constraint that the transmit CDMA downlink is usually limited by multipleaccess interference and by lbe limited number of available orthogonal spreading codes. By using Multiuser Transmission (MUT) methods in the base station in conjunction with smart antennas, the interference can be mitigated and the downlink cell capacity can be substantiallv increased. The number of snonorted users signal power is limited. Linear Zero-Forcing MUT (TxzF) concepts are known as Transmitter Precoding [Z], Joint Transmission [3], Joint PreDistortion [4l, [519 [61 O r Joint Signal Preceding [7l. The linear MMSE Transmitter or Transmit Wiener filter (TxWE) and the necessary iransmit power in the CDMA iiwnlink with linear MUT methods, like Joint Transmission, and nonlinear methods like Minimum Bit Error Rate Multiuser Transmission is investigated. By eo-locating dinerent scrambling code groups in one base station, lhe number of supported nsem is roughly proportional to the number of applied antennas, but the spatio-temporal dimension can also be exceeded in certain circumstances. Furthermore, a simplified phase-only Minimum Bit Error Rate Multiuser Transmission is proposed, including the first and second order analytic BER derivatives. The simulation environment is similar to 3GPP TDD CDMA or the Chinese TD-SCDMA

Adaptive minimum error-rate filtering design: A review

“…Provided that the desired main tap (53) and (54) Note that the main tap c d must be known in any receiver, i.e. the dth column of the system matrix H must be known in the receiver.…”

“…The MBER filtering design has also been incorporated into turbo iterative detection [51][52][53]. Other applications include the MBER transmission schemes [54][55][56], the MBER rake receiver [57,58], the MBER-based optical receiver [59][60][61][62], and the power control or allocation based on the MBER criterion [63][64][65][66]. It can be seen that the introduction of the novel MBER design has opened up a new research direction and has stimulated wide interests in the communication research community.…”

Algorithms and applications of channel impulse response length estimation for MIMO‐OFDM

“…The performance of the FCLI algorithm is investigated by computer simulations using the OFDM system parameters of the WIGWAM home/office (HO) or public access (PA) scenarios [6] listed in Table 1. or a practical distribution of timing errors.…”

MBER Space-Time Decision Feedback Equalization Assisted Multiuser Detection for Multiple Antenna Aided SDMA Systems

“…Similarly, the noise-free part of the th detector's output assumes values from the set (24) Thus can only take the values from the set (25) and can be divided into the two subsets conditioned on the value of (26) The conditional probability density function (pdf) of given is a Gaussian mixture given by [15], [16] …”

“…For the single-user single-antenna system, the minimum BER (MBER) equalization design has become popular [17]- [24], and it has been shown that the MBER DFE is less sensitive to the error propagation due to decision feedback errors compared to the MMSE DFE [24]. For the base station employing multiple transmit antennas, an MBER multiuser transmission scheme has been proposed in [25], while for the multiple antenna assisted receiver, an MBER rake receiver has been discussed in [26]. Against this background, the novelty of this paper is that the MBER ST DFE assisted MUD (ST-DFE-MUD) is proposed for the first time in the literature in the context of SDMA.…”