LR-Aided MIMO Detectors under Correlated and Imperfectly Estimated Channels

A Seysen's algorithm–based incremental lattice reduction

“…For the former, each entry of its channel matrix H is an i.i.d complex Gaussian distributed variable with zero mean and unit variance. As for the latter, by assuming the correlation between the receiving antennas and that between the transmitting antennas are independent, the channel matrix of the spatial correlated model can be obtained from the works of Valente et al 11 and Kermoal et al 35 Note that the antenna array considered in this correlated model is the uniform linear array. Therefore, based on the type of channels, two different simulation scenarios are considered and their corresponding settings are given in Table 1.…”

“…The reason is as follows. When decreases in the interval [1,11], the termination condition becomes too tight, such that, even if the correct symbol appears in the detection process, it still cannot satisfy the termination condition; thus, the algorithms carry on to process another symbol that makes the performance of the system even worse. On the other hand, increasing from the optimal point 11 can also deteriorate the performance of the SA schemes.…”

“…Observing this, the lattice reduction (LR) technique is introduced to improve their performance. [8][9][10][11] It has been proven that the LR-aided linear 12 and successive interference cancellation (SIC) 13 detectors are able to achieve the same diversity order as the ML detector, as the LR provides a near orthogonal channel matrix to reform the system model. 14 Moreover, a lot of research has been done to directly reduce the complexity of LR algorithms.…”

Cooperative multi‐cellular large MIMO over asynchronous channel training

“…These detectors can be improved by using different techniques, such as ordered successive interference cancellation [5] and lattice reduction [6]. In fact, the lattice reduction is very useful for ill-conditioned and/or high-correlated MIMO channels, besides achieving near-optimal performance while holding full diversity.…”

“…Because high-order space-time block codes are not straightforward and BLAST scheme can offer higher data rates, this one became the most popular among MIMO transmission schemes aiming to COOPERATIVE MULTI-CELLULAR LARGE MIMO OVER DESYNCHRONIZED CHANNELS 2331 realize large multiplexing gains. Furthermore, for symbol detection, a vast number of solutions can be found in literature, where some solutions, such as ordering [5] and lattice reduction [6], or even their combination, can achieve near-optimum performance, provided by the sphere decoding [7] but with an extremely reduced complexity regarding the maximum-likelihood (ML) solution, depending on the system configuration, for example, number of transmit antennas and modulation order. The dual approach for conventional detection, that is, precoding, may be preferable for concentrating the processing on the transmitter but is normally less effective as the set of processing operations is limited.…”