scholarly journals Generalised grouped minimum mean-squared error-based multi-stage interference cancellation scheme for orthogonal frequency division multiple access  uplink systems with carrier frequency offsets

2013 ◽  
Vol 7 (7) ◽  
pp. 685-695 ◽  
Author(s):  
Rui Fa ◽  
Li Zhang
Keyword(s):  
Carrier Frequency ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Mean Squared Error ◽  
Frequency Division ◽  
Minimum Mean Squared Error ◽  
Squared Error ◽  
Carrier Frequency Offsets ◽  
Multi Stage ◽  
Frequency Offsets

scholarly journals Carrier Frequency Offsets Problem in DCT-SC-FDMA System: Investigation and Compensation

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Faisal S. Al-kamali ◽  
Moawad I. Dessouky ◽  
Bassiouny M. Sallam ◽  
Farid Shawki ◽  
Fathi E. Abd El-Samie
Keyword(s):  
Carrier Frequency ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Minimum Mean Square Error ◽  
Multiple Access Interference ◽  
Low Complexity ◽  
Estimation Errors ◽  
Carrier Frequency Offsets ◽  
Frequency Offsets ◽  
The Impact

The Single-Carrier Frequency Division Multiple Access (SC-FDMA) system is a well-known system, which has recently become a preferred choice for uplink channels. In this system, the Carrier Frequency Offsets (CFOs) disrupt the orthogonality between subcarriers and give rise to Intercarrier Interference (ICI), and Multiple Access Interference (MAI) among users. In this paper, the impact of the CFOs on the performance of the Discrete Cosine Transform (DCT) SC-FDMA (DCT-SC-FDMA) system is investigated. Then, a new low-complexity joint equalization and CFOs compensation scheme is proposed to cancel the interference in frequency domain. The Minimum Mean Square Error (MMSE) equalizer is utilized in the proposed scheme. A hybrid scheme comprising MMSE equalization, CFOs compensation, and Parallel Interference Cancellation (PIC) is also suggested and investigated for further enhancement of the performance of the DCT-SC-FDMA system with interleaved subcarriers assignment. For simplicity, this scheme will be referred to as the MMSE+PIC scheme. From the obtained simulation results, it is found that the proposed schemes are able to enhance the system performance, even in the presence of the estimation errors.

scholarly journals Theoretical Analysis of Interference Cancellation System Utilizing an Orthogonal Matched Filter and Adaptive Array Antenna for MANET

2019 ◽  
Vol 8 (3) ◽  
pp. 48 ◽  
Author(s):  
Harada ◽  
Takabayashi ◽  
Kobayashi ◽  
Sakakibara ◽  
Kohno
Keyword(s):  
Theoretical Analysis ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Mean Squared Error ◽  
Matched Filter ◽  
Array Antenna ◽  
Adaptive Array ◽  
Interference Signal ◽  
Minimum Mean Squared Error ◽  
Code Division Multiple

This study provides a mathematical model and theoretical analysis of an interference cancellation system combining an orthogonal matched filter (OMF) and adaptive array antenna that is called the extended OMF (EOMF). In recent years, an increase in the number of applications of mobile ad hoc networks (MANETs) is expected. To realize a highly reliable MANET, it is essential to introduce a method for cancelling the interference from other nodes. This research focuses on a scheme based on Code Division Multiple Access (CDMA) that enables simultaneous multiple access and low latency communication. However, there are problems with deteriorating performance due to the near–far problem and the increase in the amount of interference as the number of users increases. Additionally, another problem is that the spreading sequence of each user is unknown in a MANET. The OMF is expected to be a solution to these problems. The OMF performs interference cancellation by generating and subtracting a replica of the interference signal that is contained in the received signal. However, the OMF may generate an incorrect replica in the near–far problem. The EOMF compensates for the OMF’s weakness by combining the OMF with an adaptive array antenna. In this research, optimal parameters are derived from mathematical modelling and theoretical analysis of the EOMF. Specifically, the optimal weight vector and the minimum mean squared error that allow the adaptive algorithm to converge are derived and obtained from the numerical results.

scholarly journals Iterative Intercell Interference Cancellation in MIMO Multicell Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Zhengzhen Zhang ◽  
Chao Dong ◽  
Qian Wan
Keyword(s):  
Interference Cancellation ◽  
Mean Squared Error ◽  
Base Station ◽  
Intercell Interference ◽  
Minimum Mean Squared Error ◽  
Squared Error ◽  
Pilot Allocation ◽  
Receiver Performance ◽  
Multicell Networks

An iterative intercell interference cancellation algorithm is introduced to improve the receiver performance of uplink transmission in multicell networks. At first, the uplink signal detection is performed independently in each cell according to minimum mean squared error (MMSE) criterion. Subsequently, the detection results are applied to reconstruct the transmit signals of different users and cancel their interference to neighboring cells. With the help of reconstruction results, the MMSE detection matrix of each cell is updated. The channel responses of both efficient and interference links are estimated with the help of pilots. The pilot allocation parameter is introduced to indicate the quality of channel estimation. The simulation results indicate that intercell interference can be greatly mitigated by the proposed algorithm with a moderate number of receiver antennas at the base station.

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