HW 2-1 Fading
Let wI be the power received by the mobile at distance "I" from the base station. The
probability distribution of the power at distance "I" is p(wI)=exp(-wI/mI )/mI where mI is
the mean. Assume mI is proportional to I^-3. If 10log10(mI /1 m
Chapter 1
1. In case of an accident, there is a high chance of getting lost. The transportation cost is very high each
time. However, if the infrastructure is set once, it will be very easy to use it repeatedly. Time for
wireless transmission is negligibl
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The carrier frequency of IS-95 system (also known as CDMAone) is 830
MHz, and slot length is 20 ms, whats the corresponding Doppler spread to a
car at speed 50 km per hour? Is it a slow or fast fading?
Solution:
Transmission Impairments
I-Tai Lu
Department of ECE
Polytechnic Institute of NYU
1
Contents
1. Geometric Spreading Effects
2. Multipath Effects
2.1. Frequency Selectivity
2.2. Space Selectivity
3. Doppler & Multipath Effects
(Time Selectivity)
4. Obstruct
Fundamentals of Power Electronics
Second edition Robert W. Erickson Dragan Maksimovic University of Colorado, Boulder
Fundamentals of Power Electronics
1
Chapter 1: Introduction
Chapter 1: Introduction
1.1. 1.2. 1.3.
Introduction to power processing Some
Chapter 3. Steady-State Equivalent Circuit Modeling, Losses, and Efficiency
3.1. The dc transformer model 3.2. Inclusion of inductor copper loss 3.3. Construction of equivalent circuit model 3.4. How to obtain the input port of the model 3.5. Example: inc
Chapter 2 Principles of Steady-State Converter Analysis
2.1. Introduction 2.2. Inductor volt-second balance, capacitor charge balance, and the small ripple approximation 2.3. Boost converter example 2.4. Cuk converter example 2.5. Estimating the ripple in
Chapter 4. Switch Realization
4.1. Switch applications
Single-, two-, and four-quadrant switches. Synchronous rectifiers
4.2. A brief survey of power semiconductor devices
Power diodes, MOSFETs, BJTs, IGBTs, and thyristors
4.3. Switching loss
Transistor s
National Air Express:
National Air is a competitive air- express firm with offices around the country. Frank Smith, the
Chattanooga, Tennessee, station man-ager, is preparing his quarterly budget report, which will
be presented at the Southeast regional m
Ans1. The situation and its challenges in the fall of 1989 are as follows:1. Product/Market: The portable is at least 2 years late and severely overweight and oversized. Apple
seems to have missed the market signal, through some combination of denial and
Name_ID_ (10pts)
A typical application example is given here. A radio transmitter with power 10mW and
frequency 900 MHZ is employed in a microcell. The background noise is -120dBm. The
height of mobile antenna is hm=2m and the height of base antenna is hb
Multipath and Doppler Effects and Models
(A Deterministic Approach to Broadband Channel Modeling)
There are two parts in this lecture.
In Part I, we will first introduce the mutipath propagation effects and
Doppler frequency shift/spread effects.
In Par
HW 1 sol
1)
Consider one-dimensional cellular FDMA system serving a highway and making use of
NR cells per frequency reuse region. See two examples (NR=2 and NR=3) below.
2r
Cell 1
Use f1
Cell 2
Use f2
Cell 3
Use f1
Cell 4
Use f2
Cell 5
Use f1
Cell 6
Use
HW 3-1. Multipah channel models
A transmitter transmits a signal s(t) with carrier frequency fc. The signal reaches the
receiving antennas through three paths. The path gains are a1, a2, and a3. The path delays
are t1, t2, and t3. The Doppler shifts at th
HW 3b-1 Delay Spread
There are two rays with arrival times at 10sec and 11sec. Find the power weighted
mean arrival time and power weighted delay spread (i.e., rms delay spread) for the
following two cases:
a) Power of ray 1 is equal to power of ray 2.
b)
HW 2-1 Path Loss Model
a.) A path loss model is given by the following equation
PL(d)= - nm 10*log10 (d/dm)+PL(dm), m=1,2,3,
dm <d<dm+1
Find the slopes nm and break points dm, m=1,2,3 from the following graph.
PL
-30dB
-45dB
-65dB
-83dB
25
30
35
38
x=10lo
MMSE DATA DETECTION (Transmitter Processing with Total Power Constraint)
Basic MMSE Problem:
Consider the following problem. We receive a vector y of the form
y =Hx + n
(1)
where H is the known channel matrix, x is the vector of inputs to the channel, to
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Received signal R is the sum of a bipolar signal S and an additive Random Noise N.
Here, the bipolar signal constellation for S is
either +1 (with probability p)
or 1 (with probability 1p).
And N is uniformly distributed in [-3 3]
De
Name_
The power delay profile for channel model A is
1 - 0.2t
P (t ) =
0
0 t 5( m sec)
elsewhere
And the Doppler Power spectrum is S()
If the system bandwidth is 1MHz,
a.)
b.)
c.)
d.)
What is the minimum number of taps for channel model A? (2 pts)
What
Let wI be the power received by the mobile at distance I from the base station. The probability
distribution of the power at distance I is
p(wI )=1/m I
if 0.5m I >= wI >= 1.5m I
Assume mI is proportional to I -3. If mI =8 nwatt at I=10km,
A.) find the pro
Part I
The power of two received signals r1 and r2 are non-negative random variables. When the
system threshold is 1, the outage probability of one branch (i.e., no diversity) is 0.05.
That is
Prob( ri <= 1)=0.05 where i= 1 or 2.
a.) When the correlation
De Mars Product Strategy
De Mar, a plumbing, heating, and air-conditioning company located in Fresno, California, has a
simple but powerful product strategy:
Solve the customers problem no matter what, solve the problem when the customer needs it
solved,