Adaptive Bit Allocation Algorithm for OFDM System

2014 ◽  
Vol 989-994 ◽  
pp. 2161-2164
Author(s):  
Wei Wei ◽  
Wen Dong An
Keyword(s):  
Greedy Algorithm ◽  
Bit Error Rate ◽  
Data Transmission ◽  
Transmission Rate ◽  
Bit Allocation ◽  
Total Power ◽  
Ofdm System ◽  
Allocation Algorithm ◽  
The Greedy Algorithm ◽  
Number Of Iterations

For the greedy algorithm required a large number of iterations, this paper proposed one adaptive bit allocation algorithm based on Hughes-Hartogs algorithm which was improved greedy algorithm .Under the constraint of bit error rate and data transmission rate, the algorithm first used the Chow algorithm to allocate some of the bits, and then used the greedy algorithm to allocate the remaining bits. When minimize the total power by this algorithm, the iterations of this algorithm were significantly less than the greedy algorithm. By computer simulation, the results showed that performance of this algorithm was very close to the greedy algorithm, and the number of this algorithm’s iterations was 7.4%~34% of the greedy algorithm.

A Fast Adaptive Transmit Power and Bit Allocation in OFDM System

2013 ◽  
Vol 765-767 ◽  
pp. 444-447
Author(s):  
Juan Wen ◽  
Qi Ming Tian
Keyword(s):  
Theoretical Analysis ◽  
Bit Error Rate ◽  
Error Rate ◽  
Bit Allocation ◽  
Ofdm System ◽  
Transmit Power ◽  
Allocation Algorithm ◽  
Bisection Algorithm ◽  
Simulation Results ◽  
Adaptive Transmit Power

In this paper, we propose a fast and optimal adaptive transmit power and bit allocation algorithm, which is called Bisection Searching Level (BSL) for wireless OFDMA systems. The algorithm aims at maximization of data rate under the constraints of total transmit power and bit error rate (BER). BSL is based on water pouring approach, and adopt bisection algorithm to find the water pouring level under discrete bit restriction. Both theoretical analysis and simulation results demonstrate the optimality of our proposed algorithm.

Research on Optimized Online Allocation of Scope Spatial Crowdsourcing Tasks

2020 ◽  
Vol 29 (03) ◽  
pp. 2050003
Author(s):  
Liping Gao ◽  
Kun Dai ◽  
Chao Lu
Keyword(s):  
Greedy Algorithm ◽  
Task Allocation ◽  
Specific Task ◽  
Spatial Crowdsourcing ◽  
Two Phase ◽  
Allocation Algorithm ◽  
Sensing Data ◽  
Important Branch ◽  
The Greedy Algorithm

Task allocation of spatial crowdsourcing tasks is an important branch of crowdsourcing. Spatial crowdsourcing tasks not only require workers to complete a specific task at a specified time, but also require users to go to the designated location to complete the corresponding tasks. In this paper, Scope spatial crowdsourcing task whose work position is a region rather than a location is a kind of spatial crowdsourcing task. Mobile crowdsourced sensing (MCS) is one of the most important platforms to publish spatial crowdsourcing tasks, based on which MCS workers can use smartphones to complete the collections of related sensing data. When assigning tasks for scoped crowdsourcing tasks, there is a scope overlap between tasks and one or more tasks due to the association of task scope between tasks, which causes a waste of manpower. The focus of this paper is to study the redundancy of the task scope that occurs when using MCS to collect scoping data in the case of fewer workers and more tasks. Optimizing scope spatial crowdsourcing tasks allocation algorithm (OSSA) can eliminate the redundancy of the task area by integrating and decomposing tasks and achieve the improvement of the assignable number of tasks. In the Windows platform, experiments are made to compare the efficiency of the OSSA algorithm with the greedy algorithm and the two-phase-based global online allocation (TGOA) algorithm to further prove the correctness and feasibility of the algorithm for task scope optimization.

A Novel Covert Communication Method Based on WCDMA

2013 ◽  
Vol 336-338 ◽  
pp. 1611-1615
Author(s):  
He Yi Wu ◽  
Ai Qun Hu
Keyword(s):  
Bit Error Rate ◽  
Data Transmission ◽  
Communication Systems ◽  
Transmission Rate ◽  
Base Station ◽  
Wireless Communication Systems ◽  
Covert Communication ◽  
Message Processing ◽  
Communication Method ◽  
Communication Scheme

Covert communication can effectively improve the security of communication content, which has been widely used in wireless communication systems. Most approaches for covert communication are based on the principle of text-embedded in upper layer of the OSI model. In this paper, a novel covert communication scheme is proposed. This method takes advantage of scramble codes and message processing rules of the WCDMA system. It uses a downlink scramble code in the normal WCDMA uplink signal, so that the covert messages will not be received by the base station (BS) and the user equipment (UE). Simulation result shows that the proposed covert communication method has a low bit error rate (BER) performance, and will only make the signals of different business to a slightly lower data transmission rate.

Frequency-Hopping Communication Technology Based on Self-Adaptive MIMO-OFDM System

2014 ◽  
Vol 945-949 ◽  
pp. 2230-2236
Author(s):  
Jin Xin Ruan ◽  
Yan Xu ◽  
Miao Cui
Keyword(s):  
Communication Technology ◽  
Data Transmission ◽  
Transmission Rate ◽  
Frequency Hopping ◽  
Ofdm System ◽  
Time Data ◽  
Electronic Warfare ◽  
Data Transmission Rate ◽  
Mimo Ofdm ◽  
Self Adaptive

Along with the gradual increase of intelligent and information equipment on the battlefield, the fierce electronic warfare between the enemy and us makes the electromagnetic environment of the battlefield more and more severe. The anti-jamming capability of conventional frequency-hopping communication system is inadequate such as anti-dynamic interference, anti-intercept, etc., thus posing a serious threat to normal military communication. Moreover, currently the data transmission rate of frequency-hopping system is fairly lower, and cannot meet the increasing large-capacity real-time data transmission requirements. This article deeply researches self-adaptive MIMO-OFDM technology and frequency-hopping communication technology, and introduces the research on frequency-hopping communication technology based on self-adaptive MIMO-OFDM system. The research shows that self-adaptive MIMO-OFDM-based technology can effectively enhance the frequency-hopping communication system’s anti-jamming and anti-intercepting capability, and improve the data transmission rate.

A Novel CML Latch-Based Wave-Pipelined Asynchronous SerDes Transceiver for Low-Power Application

2019 ◽  
Vol 29 (07) ◽  
pp. 2050110
Author(s):  
Mahesh Kumawat ◽  
Mohit Singh Choudhary ◽  
Ravi Kumar ◽  
Gaurav Singh ◽  
Santosh Kumar Vishvakarma
Keyword(s):  
Low Power ◽  
Data Transmission ◽  
High Speed ◽  
Frequency Synthesizer ◽  
Technology Development ◽  
Transmission Rate ◽  
Current Mode ◽  
Total Power ◽  
Single Chip ◽  
Transmission Speed

In the present technology development billions of transistors are fabricated on a single chip, which improves the performance of circuits in terms of high data transmission speed and power consumption. This requirement of data transmission speed is achieved with the help of high-speed transceivers. In this paper, we present a high-speed asynchronous wave-pipelined serializer and deserializer (SerDes) transceiver implemented using current-mode logic (CML). This asynchronous transceiver circuit does not require a clock and therefore it saves large amount of power which is consumed in the phase locked loop (PLL) and frequency synthesizer circuits. Further, the proposed design is built using CML which saves more power. CML circuit operates at relatively higher speed as compared to CMOS circuits which helps the circuit to operate at higher data rate. Compared to conventional CML latch, a novel CML latch is proposed in our design to increase the speed. The circuit is implemented in standard CMOS 65-nm technology. The total power consumed by the serializer and deserializer is 9.32[Formula: see text]mW, which is very less as compared to published related works. The proposed asynchronous SerDes transceiver operates at 18.1-Gbps data transmission rate with low power dissipation.

Relay Selection Algorithms in D2D Cluster Underlaying Cellular Networks

2015 ◽  
Vol 713-715 ◽  
pp. 1413-1418
Author(s):  
Zhi Hao Ruan ◽  
Shi Xiang Shao ◽  
Jun Sun
Keyword(s):  
Cellular Networks ◽  
Greedy Algorithm ◽  
Data Transmission ◽  
Relay Selection ◽  
Spectrum Efficiency ◽  
Selection Algorithm ◽  
Selection Algorithms ◽  
Relay Selection Algorithm ◽  
The Greedy Algorithm ◽  
Device Technology

With the development of mobile communication, D2D (Device-to-Device technology) has become a research hotpot. In this paper, we first derive the channel capacity of an n-hop link and get the formula of spectrum efficiency. And then to maximize the spectrum efficiency, we focus the algorithm of selecting the best relay for data transmission in a D2D cluster of cellular network. The algorithm proposed in this paper is an improvement of the greedy algorithm. This algorithm solves the problem that the greedy algorithm would be invalid in the case of having a big hole in the topology. At last, we could see a significant gain in terms of spectrum efficiency by using the new relay selection algorithm.

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