EE511 FALL 2006
INTRODUCTION TO COMMUNICATION SYSTEMS
12-15-06
Problem: Nodal Analysis of BPF
FINAL PROJECT
RESULTS
SECOND PLACE: SSVR, MKB, BMW
GROUP
BITS/PACKET
DATE
NUMBER GRADE
Liu&Fryman (Liu, Fryman) 131072 12-15-06 100
SSVR (Cavaturu, Boddapati, Nott, Katragadda) 32768 12-14-06 90
MKB (Mohammad, kothapally, Busa) 32768 11-30-06 90
BMW (Uttamkumar, Madanu,Muppidi)
32768 12-15-06 90
EEJGC (Dressman, Schneider, Casey) 24966 12-15-06 85
MCJT (McEwen, Gibbs, Tolliver, Desai) 16384 11-16-06 75
Bitslap (William Berry, John C. Scott) 16384 11-15-06 75
SCORING: (I boosted the scores to represent the difficulty of the problem)
This is a competitive format so the scoring is based on a dynamic scale. The score is SCORE = A * Nbit + B where A and B are determined from the following two equations:
100 = A * Nbmax + B
70 = A * 16384 + B
where Nbmax is the highest number of bits transmitted and received without error. The baseline ran at 16384 bits.
PROTOCOL for FINAL PROJECT
Student sends the bit matrix size,
modulator and demodulator m files to instructor. All the files sent to the
instructor have the "groupname" as a prefix so the instructor can
keep the track of the individual group m files and data.
1. BIT MATRIX SIZE (student sends
this to instructor): The student is ranked by the total number of bits that can
be transmitted through the channel. The bit matrix is 2 dimensional. It has a
length Nbit (column dimension) and a width of Nseq (row dimension). These values, named "Nbit" and "Nseq",
along with a character string containing "groupname",
they are stored in a file called "groupname_Bsize.mat."
An example m file is "groupname_createBsize.m".
Group sends instructor this m file to initiate test.
2. BIT MATRIX (instructor generates
this based on groupnameBsize values): The bit matrix
is generated and stored in a file called groupname_B.mat
and the matrix is called B. A sample code that will generate a
Nseq x Nbit bit matrix B is
"Bgen06.m." I will use Bgen to generate a random sequence of bits of the size
specified by the student in "groupnameBsize.mat."
3. MODULATOR (student sends the
modulator m file to the instructor): A modulator m file by the name "groupname_modulator.m"
will be sent to the instructor. Its input is the file named "groupname_B.mat." The program will create a 1 x N real
vector "s" and a Nseq x N, bit check
matrix, called "Bcheck." The signal vector
will be stored in "groupname_signal.mat"
and the bit check matrix is stored in "groupname_Bcheck.mat."
The length is N=1048576=131072*8. The Bcheck matrix (Nseq x N) has 3 element values +1 for a bit value of
"1" to be present, -1 for a bit value of "0" to be
present and 0 for "don't care."
4. CHANNEL (instructor will run
this program, channel06.m, on vector s). The channel will do
two things, lowpass filter
and then add noise. The signal vector s0 is convolved with the Butterworth low
pass filter of order 8 and fc=(N/48),
yielding a bandlimited signal vector s. The noise is
based on the value sigma=0.5*(max(s)-min(s)) and is generated by w=sigma*randn(1,N).
The noisy vector is sn=s+w.
The output of the channel will be a real one dimensional vector, "r",
of size 1xN. This r vector will be stored in groupname_r.mat.
5. DEMODULATOR/BINARIZER (student
sends the demodulator.m file to the instructor): A demodulator
file by the name "groupname_demodulator.m"
will be sent to the instructor. Its input file is groupname_r.mat.
Its output will be a Nseq x N real matrix. Each row of
the matrix will represent the demodulated and binarized
bit stream defined in B. This output will be stored in "Bs" and saved
to the file groupname_Bs.mat. NOTE: The demodulator
should also binarize the signals in Bs to have values
of either 1 or 0.
6. BIT CHECK (instructor will run bitcheck, bitcheck06.m, to test the students
data for errors): The instructor will run a program that will input the groupname_B.mat file, groupname_Bcheck.mat
file and the groupname_Bs.mat file. The program will
go to each value of 1 or -1 in the Bcheck matrix and
see if the associated element in the Bs matrix is (1) if Bcheck
is 1, then Bs value must be 1 (above 0.5), (2) if Bcheck
is -1, then Bs must be 0 (below 0.5). For each element of Bcheck
that is 0 (between -0.5 and +0.5) the associated value in Bs is ignored. The
resulting values will be verified with the B matrix. To be acceptable, there
must not be any errors in either the number of ones and zeros or the specific
bit values when compared to B. The results will be posted on the web.
Additional m files include:
V7 Mixer and DSBSC Description
FAQs
MATLAB:
- Where is a manual for MATLAB? Try the library first. Most students only use the manual in the very beginning of their MATLAB experience. Once into it, the language is intuitive enough and there are enough sample M files that learning MATLAB is somewhat self-sustaining without manuals. Type "matlab" to execute intepreter, "help ?" to see listing of operators, "help" for listing of functions, "who" to see active variables, "what" for listing of M files and always use "clear" to start over again.
- How do
you initialize the dimension of a variable? One way is to initialize its
values by zeros(M,N) or ones(M,N). Ex: A=zeros(10,8) is a 10 x 8 matrix of
zeroes. Another function is "ones" which works the same way as
"zeros". Another method is nested loop, ie.,
1:5 loops from 1 to 5 so A(1:5)=3:7 will store the values 3 to 7 in the
first 5 elements of A.
