Successive Multiuser Detection Research Articles

Polar 부호화 SCMA를 위한 순차적 다중사용자 검출 기법

Polar 부호화 SCMA를 위한 순차적 다중사용자 검출 기법

Fast Uplink Synchronization in LTE-Like Systems

We show a way to accelerate the successive multiuser detection (SMUD) algorithm for initial uplink synchronization (IUS) in an LTE-like system. We develop a new data model to pose IUS as a signal representation problem in a Fourier basis. We provide the theoretical guidelines for generating codes using the data model. Our method significantly reduces the complexity of computationally demanding multiplication steps of the SMUD algorithm.

Improved successive multiuser detection initial ranging algorithm with interference cancellation for orthogonal frequency division multiple access systems

An improved successive multiuser detection (SMUD) initial ranging (IR) algorithm with interference cancellation is presented for orthogonal frequency division multiple access systems followed by IEEE 802.16 m standard. The proposed method detects all the valid paths of IR subscriber stations, selects the path with the maximum signal-to-interference-plus-noise ratio, and estimates the parameters of the path by least-square method. The estimated parameters are further processed by the parallel interference cancellation processing to improve their accuracy, and then the signal of the selected valid path is removed from the received signal in the successive interference cancellation (SIC) process. The proposed scheme can efficiently improve the parameter estimation accuracy of the selected valid path and reduce the residual multiple access interference in the SIC process. Simulation results show that the proposed method has a much better performance than the SMUD algorithm.

A novel initial ranging algorithm for OFDMA systems using smart antenna

To improve the capacity of initial ranging (IR) users simultaneously accessing into network and enhance the performance of the IR, a novel IR algorithm is presented for the orthogonal frequency division multiple access systems with the smart antenna. The beamforming weight vectors provided by the antenna array are introduced for the IR users, and the procedures of the multiuser parameter estimation and the interference cancellation are designed. The proposed method can improve the accuracy of the channel estimation of active paths and efficiently reduce the residual multiple access interference. Simulation results show that the proposed method has a much better performance than the available successive multiuser detection and interference cancellation algorithm and accommodates more active ranging users simultaneously accessing into a cell.

Precoding-based initial ranging signal for SMUD algorithm in OFDMA systems

A novel precoding-based initial ranging signal is presented for the successive multiuser detection and interference cancellation (SMUD) algorithm in OFDMA uplink systems. The ranging codes in the multiple ranging symbols are coded by the precoding matrix. The performance of the SMUD algorithm is greatly improved by using the decoded signal of the received precoded ranging signal.

Successive multiuser detection and interference cancelation for contention based OFDMA ranging channel

In this letter, we propose a successive multiuser detector (SMUD) for contention based OFDMA ranging channel compliant to the IEEE 802.16 (WiMAX) standard. A ranging channel consists of a set of subcarriers in specific time slots shared by multiple users, so the multiple access interference (MAI) limits the performance of ranging detectors. Different from existing methods that treat the MAI as noise, the proposed SMUD successively detects the channel paths of active ranging signals and cancels their interference for further detection. This approach significantly suppresses the MAI and improves both user detection and parameter estimation performance.

Successive multiuser detection and interference cancelation for contention based OFDMA ranging channel [transactions letters

In this letter, we propose a successive multiuser detector (SMUD) for contention based OFDMA ranging channel compliant to the IEEE 802.16 (WiMAX) standard. A ranging channel consists of a set of subcarriers in specific time slots shared by multiple users, so the multiple access interference (MAI) limits the performance of ranging detectors. Different from existing methods that treat the MAI as noise, the proposed SMUD successively detects the channel paths of active ranging signals and cancels their interference for further detection. This approach significantly suppresses the MAI and improves both user detection and parameter estimation performance.