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					    RF Microelectronics

       RFIC
       Professor:
                    Dr. Ali Fotowat Ahmady
       Date:
                    July 16, 2007

       Lectures:
                    1-10 (sections 1-5)


KAVOSHCOM
Contents
1.   Introduction
2.   Basic concepts
3.   Digital modulation, Spectral control, Detection
4.   Multiple access standards, TDM, CDM, OFDM
5.   TRx architecture
6.   LNA and Mixer
7.   Oscillator
8.   Frequency Synthesizer
9.   Power Amplifier




September 17, 2011                                     2
Section One
1.    Introduction
     a. Complexities
     b. Goals
     c. Technology




September 17, 2011     3
Complexities
Simple FM Radio




September 17, 2011   4
Complexities
Philips GSM phone




September 17, 2011   5
IS-19 cellular telephone RF section block diagram

A 45 MHz offset frequency oscillator generates the required
    receiver and transmitter local oscillator frequency.




September 17, 2011                                            6
IS-55 block diagram
A narrowband IF filter is required for digital operation, as
    well as an ADC in the baseband.




September 17, 2011                                             7
Why…?
1.    IF frequency
2.    50-ohm impedance matching
3.    Shielding
4.    All-band filtering
5.    I&Q receiver
6.    Gain and phase setting in receiver
7.    I&Q transmitter
8.    LC filter for transmitter
9.    SSB mixer
10.   Out-of-band noise
11.   Output power control
12.   …




September 17, 2011                         8
Disciplines required in RF design




As the industry moves toward higher integration and lower
cost, RF and wireless design demands increasingly more
“concurrent engineering”.
September 17, 2011                                          9
RF design hexagon
The trade-offs involved in the design of such circuits can be
summarized in the “RF design hexagon”.




September 17, 2011                                          10
Then …
    In chip
       Increase frequency
       Decrease power
       Change architecture




September 17, 2011            11
Technology
    Three critical factors influencing the choice of
     technologies in the competitive RF industry:
       Performance
       Cost
       Time to market

    Issues play an important role in the decisions made by
     the designers:
       Level of integration
       Form factor
       Prior successful experience




September 17, 2011                                        12
Technology
    The technologies constitute the major section of the RF
     market:
       GaAs
       Silicon Bipolar
       BiCMOS
       SiGe
       CMOS


CMOS technology must resolve a number of practical issues:
Substrate coupling of signals that differ in amplitude by
100dB, parameter variation with temperature and process,
and devices modeling for RF operation.



September 17, 2011                                         13
Contents
1.   Introduction
2.   Basic concepts
3.   Digital modulation, Spectral control, Detection
4.   Multiple access standards, TDM, CDM, OFDM
5.   TRx architecture
6.   LNA and Mixer
7.   Oscillator
8.   Frequency Synthesizer
9.   Power Amplifier




September 17, 2011                                     14
Section Two
2.    Basic concepts
     1. Cascaded stage nonlinearity
        1. 1 dB compensation point
        2. IP3
     2. Intersymbol interference
     3. Noise figure
     4. Sensitivity and dynamic range




September 17, 2011                      15
Effects of nonlinearity
Model nonlinearity as a Taylor series expansion up to its
third order term:

               y (t )   x (t )   x (t )   x (t )
                   1            2
                                   2
                                           3
                                              3



If a sinusoid is applied to a nonlinear system:               x(t )  A cost

                     A cost       A2 cos2 t          A3 cos3 t
                                 A2                  A3
                                    1  cos 2t       3 cos t  cos 3t 
                                 2                   4

           2 A2         3 3 A3           2 A2            3 A3
y(t )           1 A 
                                  cost 
                                                  cos 2t         cos3t.
           2               4                 2               4
The term with input frequency is called the fundamental and
the higher-order terms the harmonics.
September 17, 2011                                                              16
1 dB Compression Point
The small-signal gain of a circuit is usually obtained with the
assumption that harmonics are negligible.


                                  3 3 A2
                      Gain  1 
                                    4


In RF circuit,
1-dB Compression point
defined as:
The input signal level that
causes the small-signal gain
to drop by 1 dB.


September 17, 2011                                          17
1 dB Compression Point
To calculate the 1-dB compression point, we can write from
gain equivalent:

                                3
                     20 log 1   3 A12 dB  20 log 1  1dB
                                4

That is,
                                             1
                             A1dB  0.145
                                             3

In typical front-end RF amplifiers:
The 1-dB compression point occurs around -20 to -25 dBm
(63.2 to 35.6 mVpp in a 50 Ohm system).

September 17, 2011                                               18
Desensitization and Blocking
If a small signal and a large interferer are applied to a
compressive system, the “average” gain for the small signal
is reduced:

Assume,               x(t )  A1 cos 1t  A2 cos 2t.

The output is
                              3         3        2
             y (t )   1 A1   3 A13   3 A1 A2  cos 1t  ...,
                              4         2          
Which, for      A1  A2 , reduces to
                                   3     2
                     y (t )   1   3 A2  A1 cos 1t  ....
                                   2       

September 17, 2011                                                     19
Desensitization and Blocking
The gain for the desired signal is equal to


                                  3
                       Gain  1   3 A2
                                        2

                                  2


   A decreasing function of A2 if a3<0 .
   For sufficiently large A2, the gain drops to zero, and we
    say the signal is “blocked”.
   The interferer is called a blocking signal.



Many RF receivers must be able to with stand blocking
signals 60 to 70 dB greater than the wanted signal.
September 17, 2011                                              20
 Cross Modulation
 When a weak signal and a strong interferer pass through a
 nonlinear system,

 Weak signal:              x1 (t )  A1 cos 1t
 Strong interferer:        x2 (t )  A2 1  m cos mt  cos 2t

 Then,
                3        2     m2 m2                      
y (t )  1 A1   3 A1 A2 1 
                                     cos 2mt  2m cosmt  cos1t
                                                            
                2              2   2                      

 Cross modulation is the transfer of modulation on the
 amplitude of the interferer to the amplitude of the weak signal.
 September 17, 2011                                                21
Cross Modulation
    If two signals experience nonlinearity, amplitude
     modulation in one appears in the other.

    Most important in “multi-carrier” systems. Example
     include cable TV transmitters and base station
     transmitters.




September 17, 2011                                        22
Intermodulation
    If the input sinusoid frequency is chosen such that its
     harmonics fall out of the passband,




    The output distortion appears quite small even if the
     input stage of the filter introduces substantial
     nonlinearity.


September 17, 2011                                             23
Intermodulation
Assume;          x(t )  A1 cos 1t  A2 cos 2t.
Thus,
      y (t )  1  A1 cos1t  A2 cos2t    2  A1 cos1t  A2 cos2t 
                                                                                          2


       3  A1 cos1t  A2 cos2t  .
                                          3




Expanding the left side and discarding dc terms and
harmonics, obtain the following Intermodulation products:
     1  2            2 A1 A2 cos1  2 t   2 A1 A2 cos1  2 t

                            3 A12 A2 cos21  2 t   3 A12 A2 cos21  2 t
                         3                             3
    21  2
                         4                             4
    22  1           3
                            3 A2 A1 cos22  1 t   3 A2 A1 cos22  1 t
                                2                     3     2

                         4                            4
September 17, 2011                                                                   24
Intermodulation
Intermodulation in a nonlinear system:      1 A1
                                                    3
                                                       3 A2 A12
                                                    4




Corruption of a signal due to Intermodulation between two
interferer:




September 17, 2011                                                 25
Third Intercept Point “IP3”




   IP3 is measured by two-tone test
   A is chosen to be sufficiently small so that higher-order
    nonlinear terms are negligible and the gain is relatively
    constant and equal to 1

September 17, 2011                                          26
IP3
Calculation of IP3:




• IIP3|dBm=Pinput|dBm +DPdB/2 .
• IIP3|dBm=Poutput|dBm -GaindB+DPdB/2 .
• OIP3|dBm=Poutput|dBm +DPdB/2 .

September 17, 2011                        27
The relationship between 1-dB compression point and
iip3




           A1dB   0.145
                         9.6dB
           AIP3     43



September 17, 2011                               28
Cascade nonlinear stages
Input-output characteristics of the two stage are expressed:



                                                              y2 (t )  1 y1 (t )   2 y12 (t )   3 y13 (t )

                                     y1 (t )  1 x(t )   2 x 2 (t )   3 x 3 (t )

Then,
                                
         y2 (t )  11 x(t )   3 1  21 2  2  13  3 x 3 (t )  ...
Thus,
                              4            11
                     AIP3                                   .
                              3  3 1  21 2  2  1  3
                                                       3



September 17, 2011                                                                                    29
Cascade nonlinear stages




September 17, 2011         30
Cascade nonlinear stages
   This equation readily gives a general expression for three
    or more stages:



                  1    1      12 12 12
                  2
                      2  2  2  ...
                 AIP3 AIP3,1 AIP3, 2 AIP3,3




   Typical receiver IP3 is -15 dBm.

September 17, 2011                                          31
Example
   Stage 1 is a super linear amplifier, Thus       AIP3,1=∞ .
                     Super linear



                       G

                       Stage 1            Stage 2


• AIP3,tot= AIP3,2 /11
• AIP3,tot|dBm = AIP3,2|dBm – Gain1st satge|dB.


   Thus
          If stage 1 is an amplifier,       IIP3tot =IIP32 – GdB
          If stage 1 is an attenuator,      IIP3tot =IIP32 + GdB

September 17, 2011                                                  32
  Intersymbol Interference
       Linear time-invariant systems with insufficient
        bandwidth
        distort the signal.

                  An example of such behavior:

a periodic square wave                     output with exponential tail
                             Low-pass
                               filter




   September 17, 2011                                            33
Intersymbol Interference
     With a random sequence of ONES and ZEROS as the
      input :



                     Vin   Low-pass   Vout
                             filter




September 17, 2011                                      34
Intersymbol Interference
    Each bit level is corrupted by decaying tails created by
     previous bits. Called “Intersymbol Interference” (ISI).

    Leads to higher error rate in the detection of random
     waveforms transmitted through band-limited channels

    Particularly troublesome in wireless communications
     because of narrow bandwidth allocated to each channel




September 17, 2011                                              35
Intersymbol Interference
    Methods of reducing ISI:

        In Transmitter:

                           Pulse shaping (Nyquist signaling)

        In Receiver:

                           Equalization




September 17, 2011                                             36
Input-Referred Noise
    Representation of noise by input noise generators




    The correlation between two sources must be taken into
     account


September 17, 2011                                       37
Input-Referred Noise
    An example to illustrate the idea:




      I 2 nD  g m Vn
                       2        2
                                               Vn  8kT /(3g m )
                                                 2
                                           2
                    gm I
          2            2    2
      I       nD                n   Z in
                                               I n  8kT /(3gm Zin )
                                                 2                 2
      I 2 nD  4kT (2 g m / 3)
September 17, 2011                                                     38
     Noise Figure
         Most of the front-end receiver blocks are characterized
          in terms of their “noise figure” rather the input-referred
          noise
              Noise Figure in dB:




Signal-to-noise ratio at the input      Signal-to-noise ratio at the output




                 Noise figure is a measure of how much the SNR
                  degrades as the signal passes through a system
     September 17, 2011                                             39
Calculation of Noise Figure
    SNR in is the ratio of the input signal power to the noise
     generated by the source resistance, R s, modeled by
           2
     VRS




September 17, 2011                                            40
 Calculation of Noise Figure
                                          Vin
                                             2       2
                      SNRin 
                                          VRS
                                             2       2



 Voltage gain from Vin to the input port of the circuit (node P)


                                        Av Vin2
                                         2       2
               SNRout 
                          V
                           RS
                                2
                                     (Vn  I n Rs )  Av
                                                     2
                                                            2   2



                                                         Voltage gain from P to V out

V n and I n R s are added before squaring to account for their correlation


 September 17, 2011                                                           41
Calculation of Noise Figure

                             VRS  (Vn  I n Rs )
                                 2                   2
                      NF 
                                                 2
                                           VRS
                              4kTRs
 (for the spot noise figure to emphasize the very small bandwidth )
                                       2
                             Vn,out          1
                      NF          2
         2
                               A           4kTRs
Vn,out   =Total noise at the output                      A  Av
 September 17, 2011                                                42
Calculation of Noise Figure
    Thus,
     to calculate the Noise figure,
     we divide the total output noise power by the square
     of the voltage gain from V in to V out and normalize it
     to the noise of R s.

    As an example:
     consider the single resistor, R p




September 17, 2011                                             43
Calculation of Noise Figure
    What is the noise figure of this circuit with respect to a
     source resistance R s ?


                 Vn ,out  4kT ( Rs llR p )
                         2


                          RP
                     A
                        Rs  R p
                              Rs
                     NF  1 
                              Rp
September 17, 2011                                            44
Sensitivity
    For an RF receiver:
     The minimum signal level that the system can detect
     with acceptable signal-to-noise ratio

                     SNRin    Psig / PRS
                NF         
                     SNRout    SNRout
                Psig  PRS .NF .SNRout
    The overall power is distributed across the channel
     bandwidth, B. Thus the two sides of the equation must be
     integrated over the bandwidth to obtain the total mean
     square power
                Psig ,tot  PRS .NF .SNRout .B
                                                 for a flat channel
September 17, 2011                                               45
  Sensitivity

Pin ,m in / dBm  PRS / dBm / Hz  NF / dB  SNRm in/ dB  10 log B

Minimum input level that achieves SNR   min



       4kTRs 1
 PRS 
         4 Rin
The noise power that R s delivers to the receiver

 PRS  kT  174dBm / Hz

 Assuming conjugate matching at the input

   September 17, 2011                                         46
Sensitivity

At room temperature:

Pin ,m in  174 dBm / Hz  NF  10 log B  SNRm in
          Total integrated noise of the system called

                        Noise Floor



Since P in,min is a function of the bandwidth, a receiver
may appear very sensitive because it employs a
narrowband channel



September 17, 2011                                          47
Dynamic Range (DR)
   Generally is the ratio of the maximum input level that the
    circuit can tolerate to the minimum input level at which the
    circuit provides a reasonable signal quality

   In RF design, this definition is based on the Intermodulation
    behavior and the sensitivity called :

                     Spurious-free dynamic range




September 17, 2011                                          48
Dynamic Range (DR)
    The upper end of the dynamic range is:
     The maximum input level in a two-tone test for which the
     Third-order IM products do not exceed the noise floor
                             P  PIM ,out
           PIIP3  P 
                    in
                              out

                                    2
           P  P G
            out in

           PIM ,out  PIM ,in  G
                             P  PIM ,in       3P  PIM ,in
           PIIP3  P 
                    in
                              in
                                                in

                                   2                2
    And hence,
                     2 PIIP3  PIM ,in
           P 
            in
                            3
September 17, 2011                                            49
Dynamic Range (DR)
    The input level for which the IM products become equal
     to the noise floor is:

                         2 PIIP3  F
               P ,m ax 
                in
                               3
          F  174 dBm / Hz  NF  10 log B




September 17, 2011                                        50
Dynamic Range (DR)
    SFDR is the difference (in dB) between P      in, max   and
     P in, min

                    2 PIIP3  F
             SFDR               ( F  SNRmin )
                          3

                    2( PIIP3  F )
             SFDR                  SNRmin
                           3
    SFDR represents the maximum relative level of interferers
     that a receiver can tolerate while producing an acceptable
     signal quality from a small input level

September 17, 2011                                                 51
Contents
1.   Introduction
2.   Basic concepts
3.   Digital modulation, Spectral control, Detection
4.   Multiple access standards, TDM, CDM, OFDM
5.   TRx architecture
6.   LNA and Mixer
7.   Oscillator
8.   Frequency Synthesizer
9.   Power Amplifier




September 17, 2011                                     52
Section 3
3.   Digital Modulation, spectral control, detection

     1.    Quadrature modulation and spectral control
     2.    Constant and Variable envelope signals




September 17, 2011                                      53
Aspects of Digital Modulation
    BER                      Maximizing SNR
                 (receiver)



    Power Efficiency      Avoiding Spectral Regrowth
                  (transmitter)



    Spectral Efficiency     Maximizing The Number of Channels
                     (transceiver)




September 17, 2011                                       54
Digital Modulation Trade-Offs
 higher BER          simple architecture
but complex




September 17, 2011                         55
Quadrature Modulation
    A binary data stream could be subdivided into pairs of two
     bits and each pair represented with one of four levels
     before performing modulation.

    Bits bm and bm+1 are impressed upon a single carrier



            x(t )  bm Ac cos ct  bm 1 Ac sin c t




September 17, 2011                                          56
Quadrature Modulation




   This is possible because cosωct and sinωct are
    orthogonal functions



September 17, 2011                                   57
Quadrature Modulation
Called “Quadrature Modulation” or “Qudrature Multiplexing”
This operation is illustrated:




                          I (In-phase)




                          Q (Quadrature)
            XBB




September 17, 2011                                       58
S/P Converter




September 17, 2011   59
S/P Converter




September 17, 2011   60
Quadrature Modulation
    To obtain constellation, we assume bits bm and bm+1
     are rectangular pulses with a height ±1 and write the
     modulated signal as :


                     x(t )  1 cos ct   2 sin ct

    Where 1 and 2 can each take on a value of +Ac and -Ac




September 17, 2011                                           61
Quadrature Modulation
    Signal Constellation for Quadrature Modulation




September 17, 2011                                    62
QPSK
    If the bit waveform is a rectangular pulse, a QPSK signal
     is obtained.

    One of four phases of a sinusoid is selected according
     to the symbol




                                           k
                     xQPSK  2 Ac cos(ct  )
                                            4
                     k  1,3,5,7



September 17, 2011                                            63
QPSK
    An important drawback of QPSK is large phase changes
     at the end of each symbol
                                   [-1 -1]   [1 1]




                                180° phase transition
                                 in a QPSK waveform
September 17, 2011                                      64
QPSK
    180º phase step or, equivalently, a transition between two
     diagonally opposite points in the constellation




    Such transitions are undesirable if the waveform is to be filtered
     and subsequently processed by a nonlinear power amplifier



September 17, 2011                                                   65
OQPSK
    The above drawback is OK with Offset QPSK




    Modulation with half-the-symbol-period-offset in time


September 17, 2011                                          66
OQPSK
    Phase transitions in OQPSK : only ±90º




September 17, 2011                            67
OQPSK
    Drawback:
     Differential encoding, which plays an important role in
     noncoherent receivers, is not executable in OQPSK
    So /4-QPSK is another variant of QPSK
    The /4-QPSK signal consists of two QPSK schemes,
     one rotated by 45º with respect to the other:




September 17, 2011                                             68
/4-QPSK
   The modulation is performed by alternately taking the
    output from each QPSK generator




September 17, 2011                                          69
/4-QPSK
    Possible phase transition in the constellation is 135º




September 17, 2011                                            70
MSK & GMSK

    Continuous modulation schemes such as MSK: Minimum
     Shift Keying, and GMSK, Gaussian MSK, avoid
     abrupt phase changes which;
     1. lead to a wide spectrum
     2.present difficulties in the design of power amplifiers




September 17, 2011                                         71
Constant-and Variable-Envelope-Signals
     A modulated waveform x(t )  A(t ) cos[c t   (t )]
     is said to have a constant envelope if A(t) does not vary
     with time.
     The modulation schemes described above have constant
      envelope
     Constant-and Variable-Envelope-Signals behave differently
      in a nonlinear system
     The spectrum “grows” when a variable-envelope signal
      passes through a nonlinear system
     QAM and OFDM are examples of variable-envelope signals
     which are less power efficient




September 17, 2011                                        72
Contents
1.   Introduction
2.   Basic concepts
3.   Digital modulation, Spectral control, Detection
4.   Multiple access standards, TDM, CDM, OFDM
5.   TRx architecture
6.   LNA and Mixer
7.   Oscillator
8.   Frequency Synthesizer
9.   Power Amplifier




September 17, 2011                                     73
Section 4
4.   Multiple access standards, TDM,CDM,OFDM

        a.   Duplexing
        b.   FDM/TDM/CDMA
        c.   AMPS/NA-TDMA/CDMA/UMTS
        d.   DECT/BlueTooth/11b/11a/11n/16d/15d




September 17, 2011                                74
Duplexing
    Problem: Two-way communication by a transceiver
     Answer : Duplexing

                Time-Division Duplexing (TDD)

                Frequency-Division Duplexing (FDD)




September 17, 2011                                     75
TDD
    The same frequency band is utilized for both transmit
     (TX) and receive (RX) paths, but the system transmits
      for half of the time and receives for the other half.




    Fast enough to be transparent to the user




September 17, 2011                                            76
TDM
    Merits:
          The transmitter is disabled during reception, so the
           two TX and RX paths do not interfere.
          Direct (peer-to-peer) communication between two
           transceivers, an especially useful feature in short-
           range, local area network applications, is allowed.
    Drawback:
    The strong signals generated by all of the nearby mobile
     transmitters fall in the receive band thus desensitizing the
     receiver




September 17, 2011                                           77
FDD
    Employs two different frequency bands for the transmit and
     receive paths.




    Merit:
     The “Duplexer Filter” (the two combined front-end band-pass
     filters), makes the receiver immune to the strong signals
     transmitted by other mobile units

September 17, 2011                                        78
FDD
    Drawbacks:
        Components of the transmitted signal that leak into
          the receive band are attenuated by typically only
          50dB
        Owing to the trade-off between the loss and the
          quality factor of the filters, the loss of the duplexer
          is typically higher than that of a TDD switch.
        Spectral leakage to adjacent channels in the
          transmitter output which occurs:
                When the power amplifier turns on and off to
                 save energy
                When the local oscillator driving the modulator
                 undergoes a transient
          By contrast, in TDD such transients can be timed
           to end before the antenna is switched to the power
           amplifier output.
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Multiple Access
    Problem: How to allow simultaneous communication
              among multiple transceivers

    Answer: Multiple Access Methods

            Frequency-Division Multiple Access (FDMA)
            Time-Division Multiple Access (TDMA)
            Coded-Division Multiple Access (CDMA)




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  FDMA


                       User 1

Channel
                       User 2
Number

                       User 3




  September 17, 2011            81
FDMA
    The available frequency band partitioned into many
     channels each assigned to one user




    The channel assignment remains fixed until the end of
     the call
    Principal access method in early cellular networks
     because of its relative simplicity
    Insufficient capacity in crowded areas


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TDMA
    The same band is available to each user but at different
     times (time-Division multiple access)




                      User 1


                       User 2


                       User 3




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TDMA
    Time assigned to one user           time slot :Tsl
    Time assigned to all users          Frame : Tf

    Every Tf seconds each user finds access to the channel
     for Tsl seconds




                           Speech data


              Synchronization data   Control data

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TDMA
    Problem:

     What about the data of all other users when only one
     user is allowed to transmit?

                The data stored for (Tf-Tsl) seconds and
                  transmitted as a “Burst”

                           TDMA BURST

     Data requires to be in Digital form to be buffered

     Speech compression and Coding would be allowed

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TDMA vs. FDMA
    TDMA is a power saving system since the Power
     Amplifier of the transmitter is turned on for only one
     time slot in every frame

    Even with FDD, proper timing of TDMA bursts prevents
     simultaneous enabling of the transmit and receive paths
     in each transceiver

    TDMA more complex than FDMA because of:

            A/D conversion,
              Digital modulation,
                Time slot and Frame synchronization


September 17, 2011                                            86
CDMA
    Employs Orthogonal Messages to avoid interference
    Assigns a certain code to each transceiver


                            User 1


                            User 2


                            User 3




    Each bit of Data translated to that code before modulation




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CDMA
    A special case of spread spectrum (SS) communication



            The baseband data spread over the entire
                     available bandwidth



    Also called Direct Sequence Spread Spectrum (DS-SS)
     communication

    The code is called “spreading sequence”
                                 or
                       “pseudo random noise”

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CDMA
    In the receiver, the demodulated signal is decoded by
     multiplying it by the same code

    Upon multiplication the desired signal is “dispread” with
     its bandwidth returning to its original value

    The unwanted signal remains spread




                         Correlation




September 17, 2011                                           89
CDMA
    Important Feature:
                      Soft Capacity

              Increasing the number of users only linearly
                   increases the Noise Floor

    Critical Issue:
                         Power Control

       High-power transmitter can halt communications
                     among others




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CDMA
    The receiver monitors the signal strength of each
     transmitter and periodically sends the power
     adjustment requests to each one

    Received signal levels are typically within 1 dB of each
     other

            Reduction in the average power dissipation
             of the mobile unit
            Reduction in the average interference seen by
             other users




September 17, 2011                                              91
 Wireless Standards
    Details and limits on the design of transceivers

        Some standards used in Cellular and Cordless
         systems:



            AMPS
            NADC
            CDMA
            UMTS




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AMPS-1983
    Advanced Mobile Phone Service also called
     (“1.Generation”)

        Communication method: analog
        Duplex-Method: FDD
        Multiple-Access: FDMA Band 824-849/869-894 MHz,
         832 „Channels“ with 30 kHz width
        Modulation: FM




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AMPS




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NADC
    North American Digital Cellular System
    Mobile Phone System USA (“2. Generation”)

        Communication Method: digital
        Duplex-Method: FDD
        Multiple-Access: FDMA 824-849/869-894 MHz,
                          832 „Channels“
        with 30kHz width
               combined with TDMA with 6 Users,
                  gives 4992 „traffic channels“
        Modulation: π/4-DQPSK




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NADC




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NADC




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Qualcomm CDMA (IS-95)-1994
   Mobile Phone system USA from 1994
    (“2. Generation”)

        Communication Method : digital
        Duplex-Method: FDD
        Multiple-Access:
               CDMA Band 824-849/869-894 MHz
               20 “Channels”
               with 1.25 MHz width
        Modulation: Offset-QPSK




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CDMA




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GSM
    Global System for Mobile Communication (GSM)
    Mobile Phone System of Germany from 1991
    (2nd Generation) worldwide adoption
       Communication Method: digital
       Duplex-Method: FDD
       Multiple-Access:
             FDMA Band 890-915/935-960 MHz
              125 “Channels”
             with 200kHz Bandwidth (1 “Channel” unused)
             combined with TDMA with 8 User




September 17, 2011                                     100
GSM




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GSM




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UMTS
    Universal Mobile Telephone Service (3rd generation)

            Communication Method: digital
            Duplex-Method: FDD/TDD
            Multiple-Access:
                  CDMA combined with FDMA/TDMA
                   (hierarchy dependent)
                   Band 1900-2025/2110-2200 MHz,
                   5 MHz Bandwidth
            Modulation: QPSK




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DECT
    Digital European/Enhanced Cordless Telephone
    Applied for wireless Telephone in 1991

            Communication: digital
            Duplex- Method : TDD (Timing not critical in
                                medium ranges )
            Multiple-Access:
                   FDMA band 1880-1900 MHz,
                   10 “Channels” with 2 MHz Bandwidth
                  combined with TDMA with 12 Users
                   gives 120 “traffic channels”
            Modulation: GMSK


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DECT




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DECT




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