Total power constraint equality in integer bit loading algorithms for multicarrier systems

2006 ◽  
Author(s):  
S. Panigrahi ◽  
Tho Le-Ngoc
Keyword(s):  
Total Power ◽  
Power Constraint ◽  
Multicarrier Systems ◽  
Bit Loading

Power Allocation and Relay Selection Algorithm in Multi-Relay Amplify-and-Forward Networks

2014 ◽  
Vol 513-517 ◽  
pp. 3423-3428
Author(s):  
Zhi Kang Zhou ◽  
Qi Zhu
Keyword(s):  
Power Allocation ◽  
Relay Selection ◽  
Relay Network ◽  
Total Power ◽  
Selection Algorithm ◽  
Amplify And Forward ◽  
Power Constraint ◽  
Lower Complexity ◽  
Relay Selection Algorithm ◽  
The Ideal

In this paper, an amplify-and-forward (AF) multi-relay network is considered. In order to minimize the system outage probability, a new power allocation and multi-relay selection algorithm is proposed under total power constraint and each node power constraint. In the proposed algorithm, the ideal of ordering is adopted, which leads to the remarkable decrease of the computation complexity together with simple power reallocation. Simulation results show that the proposed multi-relay selection algorithm performs close to the optimal scheme with optimal power allocation and exhaustive search (OPA-ES) but with much lower complexity.

Bit Loading Algorithm of VSF-OFCDM Wireless Communication

2014 ◽  
Vol 539 ◽  
pp. 211-219
Author(s):  
Mao Tong Xu
Keyword(s):  
Wireless Communication ◽  
Wide Band ◽  
Wireless Channel ◽  
Total Power ◽  
Subcarrier Allocation ◽  
Frequency Space ◽  
Bit Loading ◽  
Power Limit ◽  
And Performance ◽  
System Frequency

In VSF-OFCDM wireless communication, wireless channel is divided into component channels with the same frequency space according to the frequency, and the carriers on component channels are mutually orthogonal. When there are enough subcarriers, the bandwidth efficiency of the system is close to nyquist limit, which can ensure the utilization ratio of system frequency. Therefore, under the premise of ensuring orthogonal division of channels, the channels received a secondary division according to data rate requirements and power limit of business to make the frequency resource fully used and makes the total power minimal, which realizes the optimal distribution of wireless-communication system resources. The secondary division is represented by bit loading algorithmthe best bit number of subcarrier allocation in symbol period. For the characteristics of wide-band multi-media services and granular division of VSF-OFCDM wireless communication, the subject proposes the idea of business-oriented subcarrier allocation, which means that the subcarriers are divided in symbol period with the business as the dominant. Based on the idea, the paper designs service-oriented bit loading algorithm of subcarrier, byte and power combined with distribution based on channel detection, and makes verification and performance analysis on the algorithm.

scholarly journals Opportunistic Communication (Cognitive Radio) over Primary Discarded Subchannels by Applying a Double Power Distribution

2010 ◽  
Vol 2010 ◽  
pp. 1-9
Author(s):  
G. A. Medina-Acosta ◽  
José A. Delgado-Penín
Keyword(s):  
Cognitive Radio ◽  
Power Distribution ◽  
Primary User ◽  
Total Power ◽  
Radio Communication ◽  
Power Constraint ◽  
Transmission Scheme ◽  
Opportunistic Communication ◽  
Optimal Power ◽  
Channel Realization

This paper proposes the establishment of a simultaneous cognitive radio communication based on a subdistribution of power made over unselected subchannels which were discarded by the primary user through an initial optimal power allotment. The aim of this work is to show the possibility of introducing an opportunistic communication into a licensed transmission where the total power constraint is shared. The analysis of the proposed transmission scheme was performed by considering 128 and 2048 independent subchannels affected byRayleighfading, over 10,000 channel realizations, and three different signal-to-noise ratios (8 , 16 , and 24 ). From the system evaluation it was possible to find the optimal power allotment for the primary user, the subdistribution of power for the secondary user, as well as the attenuation and the capacity per subchannel for every channel realization. Moreover, thePDFandCDFof the total obtained capacities, as well as the generation of empirical capacity regions, were estimated as complementary results.

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