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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




October 18, 2011                                       2
Section One
1.    Introduction
     a. Complexities
     b. Goals
     c. Technology




October 18, 2011       3
Complexities
Simple FM Radio




October 18, 2011   4
Complexities
Philips GSM phone




October 18, 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.




October 18, 2011                                              6
IS-55 block diagram
A narrowband IF filter is required for digital operation, as
    well as an ADC in the baseband.




October 18, 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.   …




October 18, 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”.
October 18, 2011                                            9
RF design hexagon
The trade-offs involved in the design of such circuits can be
summarized in the “RF design hexagon”.




October 18, 2011                                            10
Then …
    In chip
       Increase frequency
       Decrease power
       Change architecture




October 18, 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




October 18, 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.



October 18, 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




October 18, 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




October 18, 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.
October 18, 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.


October 18, 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).

October 18, 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       

October 18, 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.
October 18, 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.
 October 18, 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.




October 18, 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.


October 18, 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
October 18, 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:




October 18, 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

October 18, 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 .

October 18, 2011                          27
The relationship between 1-dB compression point and
iip3




            A1dB   0.145
                          9.6dB
            AIP3     43



October 18, 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



October 18, 2011                                                                                      29
Cascade nonlinear stages




October 18, 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.

October 18, 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

October 18, 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




   October 18, 2011                                                  33
Intersymbol Interference
     With a random sequence of ONES and ZEROS as the
      input :



                   Vin   Low-pass    Vout
                           filter




October 18, 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




October 18, 2011                                                35
Intersymbol Interference
    Methods of reducing ISI:

        In Transmitter:

                           Pulse shaping (Nyquist signaling)

        In Receiver:

                           Equalization




October 18, 2011                                               36
Input-Referred Noise
    Representation of noise by input noise generators




    The correlation between two sources must be taken into
     account


October 18, 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)
October 18, 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
     October 18, 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




October 18, 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


 October 18, 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
 October 18, 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




October 18, 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
October 18, 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
October 18, 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

   October 18, 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



October 18, 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




October 18, 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
October 18, 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




October 18, 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

October 18, 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




October 18, 2011                                       52
Section 3
3.   Digital Modulation, spectral control, detection

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




October 18, 2011                                        53
Aspects of Digital Modulation
    BER                        Maximizing SNR
                   (receiver)



    Power Efficiency      Avoiding Spectral Regrowth
                  (transmitter)



    Spectral Efficiency     Maximizing The Number of Channels
                     (transceiver)




October 18, 2011                                         54
Digital Modulation Trade-Offs
 higher BER        simple architecture
but complex




October 18, 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




October 18, 2011                                            56
Quadrature Modulation




   This is possible because cosωct and sinωct are
    orthogonal functions



October 18, 2011                                     57
Quadrature Modulation
Called “Quadrature Modulation” or “Qudrature Multiplexing”
This operation is illustrated:




                          I (In-phase)




                          Q (Quadrature)
             XBB




October 18, 2011                                         58
S/P Converter




October 18, 2011   59
S/P Converter




October 18, 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




October 18, 2011                                             61
Quadrature Modulation
    Signal Constellation for Quadrature Modulation




October 18, 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



October 18, 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
October 18, 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



October 18, 2011                                                     65
OQPSK
    The above drawback is OK with Offset QPSK




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


October 18, 2011                                            66
OQPSK
    Phase transitions in OQPSK : only ±90º




October 18, 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:




October 18, 2011                                               68
/4-QPSK
   The modulation is performed by alternately taking the
    output from each QPSK generator




October 18, 2011                                            69
/4-QPSK
    Possible phase transition in the constellation is 135º




October 18, 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




October 18, 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




October 18, 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




October 18, 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




October 18, 2011                                   74
Duplexing
    Problem: Two-way communication by a transceiver
     Answer : Duplexing

                  Time-Division Duplexing (TDD)

                  Frequency-Division Duplexing (FDD)




October 18, 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




October 18, 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




October 18, 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

October 18, 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.
October 18, 2011                                            79
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)




October 18, 2011                                          80
  FDMA


                     User 1

Channel
                     User 2
Number

                     User 3




  October 18, 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


October 18, 2011                                             82
TDMA
    The same band is available to each user but at different
     times (time-Division multiple access)




                      User 1


                       User 2


                       User 3




October 18, 2011                                           83
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

October 18, 2011                                           84
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

October 18, 2011                                              85
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


October 18, 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




October 18, 2011                                           87
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”

October 18, 2011                                           88
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




October 18, 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




October 18, 2011                                             90
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




October 18, 2011                                                91
 Wireless Standards
    Details and limits on the design of transceivers

        Some standards used in Cellular and Cordless
         systems:



             AMPS
             NADC
             CDMA
             UMTS




October 18, 2011                                        92
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




October 18, 2011                                       93
AMPS




October 18, 2011   94
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




October 18, 2011                                      95
NADC




October 18, 2011   96
NADC




October 18, 2011   97
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




October 18, 2011                                98
CDMA




October 18, 2011   99
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




October 18, 2011                                       100
GSM




October 18, 2011   101
GSM




October 18, 2011   102
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




October 18, 2011                                           103
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


October 18, 2011                                             104
DECT




October 18, 2011   105
DECT




October 18, 2011   106

				
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