We focus on the performance analysis of the buffer-aided relaying system which allows data and energy packets to arrive independently and depart interactively. First, we profile the cooperative relaying system model as a data arrival and energy arrival coupling queuing model. Considering the influence of channel condition on the data departure rate, a new relay transmit protocol which permits exhausting more energy packet to send one data packet in the bad channel environment is proposed. Second, the joint data packet and energy packet handling problem is ascribed to a Coupled Processor Queuing Model which could achieve its steady state transition probability by Quasi-Birth and Death method. Third, the expressions of throughput, delay, and packet drop rate for both data queue and energy queue are also derived. Simulations are demonstrated to verify the analytical results under different data arrival rate, energy arrival rate, and relaying strategy.
Cooperative relaying has fascinating charm in wireless communication networks for boosting system performance parameters significantly in the last decade [
The authors in [
Energy harvesting (EH) technique [
The authors in [
In this paper, we focus on the performance analysis of data arrival and energy arrival coupling queuing model for cooperative relaying networks. First, we profile the relaying system model with data packet and energy packet independent arrival but interactive departure. Considering the influence of channel condition on the data departure rate, a new relay transmit protocol which allows exhausting more energy packet to send one data packet in the bad channel environment is proposed. Second, the joint data packet and energy packet handling problem is ascribed to a Coupled Processor Queuing Model which could achieve its steady state transition probability by Quasi-Birth and Death method. Third, the expressions of throughput, delay, and packet drop rate for both data queue and energy queue are also derived.
The main contributions of the work are summarized below: We proposed a new relay adaptive power transmission protocol for data arrival and energy arrival coupling queuing model in cooperative relaying networks. Considering the tradeoff between data delay and energy consumption, we can sacrifice more energy packets to decrease data packet delay when the channel condition is bad and there is sufficient energy. Compared with traditional performance analysis of relaying networks, we consider the communication scenario with causal CSI and causal ESI. For practical significance, we expect that data and energy arrival obey Bernoulli distribution or to say that they do not always have data traffic to be sent. With the help of the data buffer and energy buffer, we can take into account the tradeoff between energy consumption and data packet sojourn time to achieve the better system performance in time varying channel surroundings. Different from conventional relaying system, we jointly investigate the relaying node with independent to arrive but interactive to depart data packet and energy packet. The cooperative relaying system model which allows data arrival and energy arrival coupling queuing is profiled as a Coupled Processor Queuing Model. Applying the method of Quasi-Birth and Death Process, we can derive the expressions of system performance parameters such as throughput, delay, and packet drop rate for both data queue and energy queue. Some conclusions which can strengthen the system performance with the cost of redundant energy expenditure are discussed.
The remainder of this paper is organized as follows. In Section
In this section, we first introduce the adopted system model and the performance measure. A new relay transmit protocol for data arrival and energy arrival coupling queuing model in a cooperative relaying networks is also proposed. Then, the coupling queuing model is profiled.
In this paper, we focus on the performance analysis in such a scenario including one source, one EH buffer-aided relay, and
Cellular wireless networks with buffer-aided relaying system; (a) the scenario of data packet and energy packet independent arrival but interactive departure; (b) the queuing model of (a).
The available overall frequency spectrum bandwidth is
Compared with traditional relay transmit protocol with Constant Power Transmission (CPT) strategy, the proposed new relay transmit protocol adopts an adaptive power transmission (APT) strategy which can strengthen the system performance with the cost of redundant energy expenditure. The whole transmission cycle is divided into two time slots for the new relay protocol. In the first time slot, each user transmits its data packet to relay if the data buffer of user is not empty. In particular cases there are maybe several users transferring their data packet to relay during the
Traditional wireless communication system model [
Because the EH process is a successive process which is not convenient to profile, we profile the EH process as a discrete process with unit energy
However, if the average channel gain
In the relay APT protocol, the numerical value of
The corresponding channel condition threshold is deduced by Shannon equation as follows:
According to the corresponding channel condition threshold in (
Assuming the same with [
The average data queue length of CPQM when
Average data queue length with
Average data queue length with
For the two-dimension Markov process
In this section, we first redistrict the state space of two-dimension Markov process of the data arrival and energy arrival coupling queuing model. Then, the submatrix of transition probability is defined and solved, respectively.
Firstly, we redistrict the state space of two-dimension Markov process
In order to decide the departure with data packet and the energy packet coupled, we should consider the four possible arrivals conditions which are defined as follows:
The submatrix of transition probability
More complicated than
Second, the submatrix of transition probability
The third part of submatrix of transition probability
The same as with
We can adopt the same method to acquire the submatrix of transition probability
We define the steady state distribution (SSD) of the CQPM as
In order to obtain the SSD of the CQPM quickly, we usually set the initial value of
After much effort, we can deduce some performance parameters such as average throughput, average delay, and average drop rate for the CQPM by using formula (
The average delay of the data queue and energy queue can be acquired as
The average drop rate of the data queue and energy queue can be acquired as
We have deduced the performances of average queue length, average throughput, average delay, and average drop rate about both data packet and energy packet for the CQPM in the previous sections. In this section, we will compare the deduced performances of the CQPM with the performances profile which is obtained by Monte-Carlo method and then analyze the physical significance of them which may provide a guide for the real system. Without loss of generality, the buffer sizes of data queue are
Seen from Figure
Figure
Figure
The average queue length performance of CPQM with average data arrival and energy arrival when
Average data queue length
Average energy queue length
Also shown in Figure
The average data throughput performance of CPQM with average data arrival and
Average data throughput with
Average data throughput with
We see from Figure
The average data delay performance of CPQM with
Average data delay with
Average data delay with
Also shown in Figure
The average data drop rate performance of CPQM with
Average data drop rate with
Average data drop rate with
According to Figures
The average system performance of CPQM with fixed
This paper focuses on the performance analysis of joint data packet and energy packet handling model for cooperative relaying networks. After describing the relaying system model, a new relay transmit protocol which considers the influence of channel condition on the data departure rate is proposed. The data arrival and energy arrival coupling queuing problem is ascribed to a Coupled Processor Queuing Model. Applying Quasi-Birth and Death method, the steady state transition probability of the data and energy coupled model is obtained and the expressions of relaying system performance parameters are also derived. Simulations are demonstrated to verify the analytical results under different data arrival rate, energy arrival rate, and relaying strategy. In particular, a better throughput/delay-energy expedition tradeoff is obtained when channel condition is bad. But the APT strategy with the biggest
The authors declare that they have no conflicts of interest.
The work is supported by Natural Science Foundation of China (61571234, 61401225), National Program on Key Basic Research Project (no. 2013CB329005), Jiangsu Provincial National Science Foundation (BK20140894), the Key Projects of Support Program for Outstanding Youth Talent of Universities in Anhui Province (gxyqZD2016123), and Youth Foundation of Anhui Polytechnic University (2012YQ39, 2014YQ40).