g. 1. Multi-cell wireless powered communication network architecture
As shown in Fig. 1, we consider a multi-cell full duplex (FD) Wireless Powered Sensor Network (WPSN), which consists of K Hybrid Access Points (HAPs) denoted by K = {1, 2, ..., K} and L users, i.e., sensors denoted by L = {1, 2, ..., L}.
All the users and HAPs are equipped with a single full-duplex antenna, which is used for simultaneous energy reception/transmission and information transmission/reception.
The HAPs are connected to a stable power supply and continuously transmit energy to the users. The users harvest this energy and store it in a rechargeable battery of capacity B_(max).
The users harvest energy from all the HAPs; however, they transmit their information to one HAP to which they are connected. The set of users connected to HAP k is denoted by L^(k) for k in K such that ∪ u_(k in K) L^(k) = L.
Multiple users from different cells can transmit their information concurrently; however, consider a time division multiple access (TDMA) protocol within each cell for the uplink information transmission. The total time during which the system remains operational is partitioned into frames, and each frame is further divided into M variable length non-overlapping time slots. Due to TDMA protocol, there is no intra-cell interference except self-interference caused due to FD operation.
Concurrently transmitting users from different cells may interfere with each other. The downlink energy transfer and the uplink information transmission channels are assumed to be different and block fading, i.e., the channel gains remain unchanged within a frame and can vary independently in the subsequent frames.
The downlink channel gain from HAP k to user l is denoted by h_(k)^(l). The uplink channel gain from user l to HAP k is denoted by g_(l)^(k).
EEE413 Wireless Sensor Networks - Fall 2023
Assume an on-off transmission model, in which users either transmit their information at a constant power P_(max) or remain silent if they cannot afford the transmission at P_(max) power.
Use the Shannon channel capacity formulation for additive white Gaussian noise (AWGN) channels to calculate the transmission rate x_(l) of user l as a function of SNR as
x_(l) = Wlog_(2)(1 + (g_(l)^(k(l))P_(max))/(N_(0)W + ∑_(j!=l) P_(j)g_(j)^(k(l)) + βP_(h))
where N_(0) is the noise power, W is the bandwidth of the channel, k(l) is the HAP to which user l is connected, P_(j) is the transmit power of a user j (which is equal to P_(max) if it transmits concurrently with user l or 0 otherwise), β is the self-interference coefficient, and P_(h) is the radiated power by the HAP. Note that full-duplex results in self-interference at the HAP, expressed by the term βP_(h), due to simultaneous energy transfer and information reception. The term ∑_(j!=l) P_(j)g_(j)^(k(l)) expresses the interference on the transmission of user l from the users in other cells.
Tasks
Consider the system model described above. You can work on Minimum Length Scheduling (MLS) or Sum Throughput Maximization (STM) problems. Choosing one of these objectives, complete the following tasks.
Design a scheduling algorithm to solve MLS or STM problem based on your choice.
Provide a pseudocode for your algorithm. You can check for the journal articles shared for algorithm pseudocode examples. Describe the algorithm in detail by referring to your pseudocode.
Implement the algorithm in MATLAB as a function that will take any parameters as arguments and create the schedule as an output.
System Model and Assumptions
Inter-cell Interference Information Transfer
HAP
HAP
Energy Transfer
g. 1. Multi-cell wireless powered communication network architecture
As shown in Fig. 1, we consider a multi-cell full duplex (FD) Wireless Powered Sensor Network (WPSN), which consists of K Hybrid Access Points (HAPs) denoted by K = {1, 2, ..., K}, and L users, i.e., sensors denoted by L = {1, 2, ..., L}. All the users and HAPs are equipped with a single full-duplex antenna, which is used for simultaneous energy reception/transmission and information transmission/reception. The HAPs are connected to a stable power supply and continuously transmit energy to the
The users harvest energy from all the HAPs; however, they transmit their information to one HAP to which they are connected. The set of users connected to HAP k is denoted by
Multiple users from different cells can transmit their information concurrently; however, consider a time division multiple access (TDMA) protocol within each cell for the uplink information transmission. The total time during which the system remains operational is
overlapping time slots. Due to TDMA protocol, there is no intra-cell interference except self-interference caused due to FD operation. Concurrently transmitting users from different cells may interfere with each other. The downlink energy transfer and the uplink information transmission channels are assumed to be different and block fading, i.e., the channel gains remain unchanged within a frame and can vary independently in the subsequent frames. The downlink channel gain from HAP to user I is denoted by h- The uplink channel gain from user I to HAP k is denoted by g-
EEE413 Wireless Sensor Networks - Fall 2023
Assume an on-off transmission model, in which users either transmit their information at a constant power Pmax or remain silent if they cannot afford the transmission at Pmax power. Use the Shannon channel capacity formulation for additive white Gaussian noise (AWGN) channels to calculate the transmission rate of user 1 as a function of SNR as gh(1) Pmax = Wlog2 (1) NoW + P;g() + 3Pb where N, is the noise power, W is the bandwidth of the channel, (I) is the HAP to which user 1 is connected, P is the transmit power of a user j (which is equal to Pmax if it transmits concurrently with user I or 0 otherwise), / is the self-interference coefficient, and P, is the radiated power by the HAP. Note that full-duplex results in self-interference at the HAP, expressed by the term 3P, due to simultaneous energy transfer and information expresses the interference on the transmission of user 1 from the users in other cells.
Tasks Consider the system model described above. You can work on Minimum Length Scheduling MLS) or Sum Throughput Maximization (STM) problems. Choosing one of these objectives, complete the following tasks.
1) Design a scheduling algorithm to solve MLS or STM problem based on your choice. Provide a pseudocode for your algorithm. You can check for the journal articles shared for algorithm pseudocode examples. Describe the algorithm in detail by referring to your pseudocode. 2) Implement the algorithm in MATLAB as a function that will take any parameters as arguments and create the schedule as an output.
