On Capacity of 60GHz TH-PPM Systems in Frequency Selective Fading Channels

2012 ◽  
Vol 433-440 ◽  
pp. 5506-5511 ◽  
Author(s):  
Na Li ◽  
Hao Zhang ◽  
Jing Jing Wang ◽  
T. Aaron Gulliver
Keyword(s):  
Fading Channels ◽  
Fading Channel ◽  
Channel Model ◽  
Selective Fading ◽  
Pulse Modulation ◽  
Frequency Selective Fading ◽  
Single User ◽  
Frequency Selective ◽  
Performance Results ◽  
Channel Properties

Two pulse waveforms are designed and analyzed for 60GHz pulse modulation systems. An indoor frequency selective fading channel model is introduced for single user 60GHz TH-PPM systems. The capacity with this channel model of a 60GHz TH-PPM system based on the designed pulses is derived. Performance results are presented to illustrate the effects of the pulse waveforms and channel properties on the channel capacity.

Split Channel Two-Tone On-Off Keying for Internet of Things Communication in Fading Channel

2020 ◽  
Vol 17 (7) ◽  
pp. 3207-3211
Author(s):  
Gun-Ho Lee ◽  
Eui-Rim Jeong
Keyword(s):  
Internet Of Things ◽  
Urban Area ◽  
Fading Channels ◽  
Fading Channel ◽  
Communication Systems ◽  
Urban Environments ◽  
Selective Fading ◽  
Communication Performance ◽  
Frequency Selective Fading ◽  
Frequency Selective

In medical treatment, healthcare and home appliances, the demand for Internet of Things (IoT) services is increasing in urban areas. However, in fading environments of urban area, the existing IoT communication system can degrade severely. The purpose of this paper is to develop a new IoT communication technology that improves communication performance in fading channels. IoT communication systems are aiming at low power long distances. In addition, the amount of data transmission is small due to the service requirements. To achieve this goal, existing IoT communication modems are designed with narrowband signals. However, narrowband signals may cause performance degradation in a frequency selective fading channel environments in urban area. In this paper, we propose a split channel two tone OOK (SC-TT-OOK) that implements on-off keying (OOK) using two tones. Unlike the existing OOK by using one tone, SC-TT-OOK uses spaced two tones to improve communication performance in fading channels. The conventional OOK method has a similar characteristic to that of the existing IoT modems with a narrow bandwidth spectrum. The proposed SC-TT-OOK is OOK using two separated tones. Since the proposed modulation uses two tones, it requires twice the frequency resources of the conventional OOK. However, if the frequencies of the two tones are sufficiently spaced apart, frequency diversity gain can be achieved in the frequency selective fading channels, and communication reliability can be improved in urban environments. The proposed SC-TT-OOK is examined through computer simulation. The simulation results show that the proposed scheme outperforms the conventional scheme in the frequency selective fading channel. Therefore, the proposed method can be used as an alternative technique for IoT modem in urban environments.

scholarly journals Variable Forgetting Factor LS Algorithm for Polynomial Channel Model

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Amit Kumar Kohli ◽  
Amrita Rai ◽  
Meher Krishna Patel
Keyword(s):  
Fading Channels ◽  
Fading Channel ◽  
Channel Model ◽  
Time Varying ◽  
Selective Fading ◽  
Forgetting Factor ◽  
Frequency Selective Fading ◽  
First Order ◽  
Variable Forgetting Factor ◽  
Frequency Selective Fading Channels

Variable forgetting factor (VFF) least squares (LS) algorithm for polynomial channel paradigm is presented for improved tracking performance under nonstationary environment. The main focus is on updating VFF when each time-varying fading channel is considered to be a first-order Markov process. In addition to efficient tracking under frequency-selective fading channels, the incorporation of proposed numeric variable forgetting factor (NVFF) in LS algorithm reduces the computational complexity.

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