Coursework EE401: Advanced Comm. Theory
Part-B
“Localisation of Wireless Signals”
1 Aim
The aim of this coursework is to implement and compare the main classical & modern localisation algorithms of wireless signals.
2 Software
• PC (operating system Windows 10 or Mac OS)
• MATLAB
• Personal data file that should be downloaded from the shared Box link.
3 Tasks
With reference to Figure 1, consider a transmitter (Tx) located at an unknown location rm ∈ R3×1 on the x-y plane (i.e., unknown range ρ and azimuth θ). Furthermore, consider 4 receivers (Rx) at known locations with Cartesian coordinates r1, r2, r3, r4 given in meters as follows
The objective is to estimate rm or (ρ, θ) based on the environment described in the fol- lowing 4 tasks under the line-of-sight (LOS) condition.
Figure 1: Illustration of R2 localisation with distributed Rxs
Some of the system parameters used for the provided data are summarised below:
|
Parameter
|
|
Value
|
Parameter
|
|
Value
|
|
Carrier frequency
|
Fc
|
2.4 GHz
|
Propagation speed
|
c
|
3 × 108 m/s
|
|
Symbol duration
|
Tcs
|
5 ns
|
Path Loss exponent
|
α
|
2
|
|
Number of Rx
|
N
|
4
|
SNR
|
|
20 dB
|
|
Noise power
|
σ 2
|
5 dB
|
Sampling period
|
Ts
|
5 ns
|
Task-1: Time-based Localisation
Consider that all 4 Rxs use a single isotropic antenna with unity gain:
• Time of Arrival (TOA) Localisation
Assume the transmission time instant t0 of the Tx signal is known by the Rxs, i.e. Tx & Rxs are synchronised. Provided with a data set of 256 samples and the transmission time instant t0 = 20Ts, estimate the Tx’s location using TOA localisation.
• Time Diference of Arrival (TDOA) Localisation
Assume the transmission time instant t0 is unknown and cannot be estimated. Using the same data file as above, estimate the Tx’s location using TDOA localisation.
Task-2: Received Signal Strength (RSS) Localisation
Consider that all 4 Rxs use a single isotropic antenna with unity gain and the transmit power PTx = 150 dBm. Using the data file provided for this task, estimate the Tx’s location using RSS localisation.
Task-3: Direction of Arrival (DOA) Localisation
Consider that all 4 Rxs use a Uniform Circular Array (UCA) formed by 6 omnidirectional antennas (see Figure 2) whose geometry with respect to its own reference point is given below in meters
2
rUCA = l
0.1250 0.0625 −0.0625 −0.1250 −0.0625 0.0625
0 0.1083 0.1083 0 −0.1083 −0.1083
0 0 0 0 0 0
3 5 .
(2)
Using the data file provided for this task, estimate the Tx’s location using DOA local- isation.
Figure 2: Illustration of R2 DOA localisation with distributed UCAs
Task-4: Large Aperture Array Localisation
Consider that all 4 Rxs use a single isotropic antenna with unity gain, they form a dis- tributed array of 4 elements. Using the data file provided for this task, estimate the Tx’s location using large aperture array localisation.
4 Deliverables
1. MATLAB file(s) - with brief comments. That is four MATLAB script files (one per task) where the system parameters are defined and a number of MATLAB functions (with comments) are called.
2. A pdf file with the results, including positioning circles/hyperbolic curves, of the above four tasks supported by 2-5 lines of brief comments per task.
3. Comments, if any, of how to run the programs to observe the results of the four tasks.
4. Please upload a zip file (including all the files) named by your login name (e.g., kl209.zip).
5 N.B.:
1. Personal data file: Please download your personal data file from the shared Box link.
2. In folders of Tasks 1 and 2, the “Rx1.mat”, “Rx2.mat”, “Rx3.mat” and “Rx4.mat” files contain the received signal sample vector at each Rx (antenna) in the following form.
[x[1] , x [2] ,...,x [l] ,...,x [L]] ∈ C1×L (3)
3. In folder of Task 3, the “Xmatrix i DFarray.mat” file contains the received signals in the form of the following matrix:
[xi[1] , xi[2] , . . . ,xi[l] , . . . ,xi[L]] ∈ C6×L (4)
where xi[l] ∈ C6×1 is the l-th signal snapshot of the the antenna array in the i-th Rx (8i = 1, 2, 3,4).
4. In folder of Task 4, the “Xmatrix LAA.mat” file contains the large aperture array received signals in the form of the following matrix:
[x [1] , x [2] , . . . ,x [l] , . . . ,x [L]] ∈ C4×L (5)
6 References
1. Lecture Notes on Advanced Communication Theory
2. Your own references