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

Author(s):  
S. Panigrahi ◽  
Tho Le-Ngoc
2014 ◽  
Vol 513-517 ◽  
pp. 3423-3428
Author(s):  
Zhi Kang Zhou ◽  
Qi Zhu

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.


2014 ◽  
Vol 539 ◽  
pp. 211-219
Author(s):  
Mao Tong Xu

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.


2010 ◽  
Vol 2010 ◽  
pp. 1-9
Author(s):  
G. A. Medina-Acosta ◽  
José A. Delgado-Penín

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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