scholarly journals On the Performance of Cognitive Satellite-Terrestrial Relay Networks with Channel Estimation Error and Hardware Impairments

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3292 ◽  
Author(s):  
Kefeng Guo ◽  
Kang An ◽  
Bangning Zhang ◽  
Yuzhen Huang ◽  
Daoxing Guo
Keyword(s):  
Channel Estimation ◽  
Signal To Noise Ratio ◽  
Estimation Error ◽  
Relay Network ◽  
Channel Estimation Error ◽  
High Signal ◽  
Signal To Noise ◽  
Decode And Forward ◽  
Estimation Errors ◽  
Hardware Impairments

This paper investigates the joint impact of channel estimation errors (CEEs) and hardware impairments (HIs) on the performance of a cognitive satellite-terrestrial relay network (CSTRN), where the terrestrial and satellite links are considered following Rayleigh fading and shadowed Rician (SR) fading distributions, respectively. Besides, the terrestrial relay is working in half-duplex decode-and-forward (DF) mode. By employing a general and practical model to account for both the CEEs and HIs at each link, the end-to-end signal-to-noise-plus-distortion-and-error ratio (SNDER) is first obtained for the CSTRN. Then, closed-form expressions for the outage probability (OP) and throughput of the CSTRN are obtained, which allows us to demonstrate the aggregate impact of CEEs and HIs. In order to gain insightful findings, we further elaborate on the asymptotic OP and throughput at the high signal-to-noise-ratio (SNR) condition and quantitatively determine the fundamental performance ceiling. Finally, Monte Carlo (MC) computer simulations are provided to verify the correctness of the analytical results. Besides, with representative numerical analysis’s help, interesting findings are presented.

Performance Analysis of OFDM Channel System

2011 ◽  
Vol 268-270 ◽  
pp. 1438-1446
Author(s):  
Zhang Lei ◽  
Cong Feng Liu ◽  
Wei Jiang ◽  
Gui Zhou Xu ◽  
Ning Dai
Keyword(s):  
Channel Estimation ◽  
Correlation Coefficient ◽  
Signal To Noise Ratio ◽  
Estimation Error ◽  
Error Model ◽  
Channel Estimation Error ◽  
Ofdm Systems ◽  
Signal To Noise ◽  
Estimation Scheme ◽  
Complex Correlation

OFDM is a promising digital communications technique for high data rate transmissions. In this paper, we have analyzed the performance of mobile OFDM systems in the presence of channel estimation error. A new channel estimation error model is presented. Based on the estimation error model, new and simple expressions for the average bit error probability of M-QAM OFDM systems are derived for zero-forcing, minimum mean square error and maximum likelihood receivers. A complex correlation coefficient is used to quantify the quality of the channel estimation scheme. We have shown that if the complex correlation coefficient is a function of the signal to noise ratio, then the inter-carrier interference caused by channel variations is the dominant source of performance degradation. On the other hand, if the channel estimation scheme produces a constant value for the complex correlation coefficient (estimation quality is not a function of the signal to noise ratio), then the channel estimation error will cause an error floor that is larger than the one caused by the inter-carrier interference, and is considered as one of the dominant causes of degradation. And channel estimation using pilot symbols are discussed in terms of different pilot symbol placement schemes.

Uplink Power-Domain Non-Orthogonal Multiple Access (NOMA)

2020 ◽  
Vol 12 (4) ◽  
pp. 65-73
Author(s):  
Faeik T. Al Rabee ◽  
Richard D. Gitlin
Keyword(s):  
Channel Estimation ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Estimation Error ◽  
Channel Estimation Error ◽  
Estimation Errors ◽  
Channel Estimation Errors ◽  
Fifth Generation ◽  
Power Domain

Non-orthogonal multiple access (NOMA) has been proposed as a promising multiple access (MA) technique in order to meet the requirements for fifth generation (5G) communications and to enhance the performance in internet of things (IoT) networks by enabling massive connectivity, high throughput, and low latency. This paper investigates the bit error rate (BER) performance of two-user uplink power-domain NOMA with a successive interference cancellation (SIC) receiver and taking into account channel estimation errors. The analysis considers two scenarios: perfect (ideal) channel estimation and a channel with estimation errors for various modulations schemes, BPSK, QPSK, and 16-QAM. The simulation results show that, as expected, increasing of the modulation level increases the SIC receiver BER. For example, at a signal-to-noise ratio (SNR) of 5 dB for perfect channel estimation and QPSK modulation, the user that is detected first has a BER of 0.005 compared to 0.14 for the user that is detected with the aid of the SIC receiver. Similarly, the BER of QPSK, assuming 0.25 channel estimation error of user 1, is equal to 0.06 at SNR = 15 dB compared to 0.017 for perfect estimation.

EE-RS and PA for untrusted relay network at high signal-to-noise ratio regime

2016 ◽  
Vol 10 (16) ◽  
pp. 2143-2148 ◽  
Author(s):  
Houman Zarrabi ◽  
Ali Kuhestani ◽  
Majid Moradikia
Keyword(s):  
Signal To Noise Ratio ◽  
Relay Network ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Untrusted Relay

scholarly journals Impact of Hardware Impairments with Imperfect Channel Estimation for Cache-Enabled UAV Relaying Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Dan Deng ◽  
Yanyi Rao ◽  
Fusheng Zhu
Keyword(s):  
Channel Estimation ◽  
Outage Probability ◽  
Estimation Error ◽  
Channel Estimation Error ◽  
Error Floor ◽  
Asymptotic Results ◽  
Distortion Factor ◽  
Hardware Impairments ◽  
Imperfect Channel Estimation ◽  
Hardware Impairment

The effects of hardware impairments with imperfect channel estimation for cache-enabled UAV networks are studied in this paper. The effects of the setup parameters, such as the number of cached or relaying nodes, the hardware impairment factor, the channel estimation error, and the transmission SNR, on the outage probability are present by deriving the exact closed-form expressions on outage probability. Also, the asymptotic results are present when the transmission SNR is large enough. From the asymptotic analysis, we can see that there is an error floor introduced by the hardware impairments and imperfect channel estimation. Specifically, the error floor is dependent on the channel estimation error factor, the hardware impairment distortion factor, and the QoS requirements. And the diversity order of the error floor for the cached/relaying links is equal to the number of cached/relaying UAV nodes.

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