dc

Recommendations

Info

Linear Block Codes – example 1: • For example a (4,2) code, suppose; G 1 0 0 1 1 0 1 1 a1 = [1011] a2 = [0101] • For d = [1 1], then; c 1 0 _ 1 0 1 _ 1 1 0 _ 1 1 1 _ 0 Linear Block Codes – example 2: • A (6,5) code wit h 1 0 0 0 0 1 0 1 0 0 0 1 G 0 0 1 0 0 1 0 0 0 1 0 1 • Is an even 0 single 0 0 parity 0 1 code 1 Systematic Codes: • For a systematic block code the dataword appears unaltered in the codeword – usually at the start • The generator matrix has the structure, 1 0 G .. 0 0 1 .. 0 .. .. .. .. 0 0 .. 1 p p p 11 21 .. k1 p p p 12 22 .. k 2 .. .. .. .. p p p 1R 2R .. kR I | P
R = n - k • is often referred to as parity bits I is k*k identity matrix. Ensures data word appears as beginning of codeword P is k*R matrix. Decoding Linear Codes: • One possibility is a ROM look-up table • In this case received codeword is used as an address • Example – Even single parity check code; Address Data 000000 0 000001 1 000010 1 000011 0 ……… . • Data output is the error flag, i.e., 0 – codeword ok, • If no error, data word is first k bits of codeword • For an error correcting code the ROM can also store data words • Another possibility is algebraic decoding, i.e., the error flag is computed from the received codeword (as in the case of simple parity codes) • How can this method be extended to more complex error detection and correction codes? Parity Check Matrix: • A linear block code is a linear subspace S sub of all length n vectors (Space S) • Consider the subset S null of all length n vectors in space S that are orthogonal to all length n vectors in S sub • It can be shown that the dimensionality of S null is n-k, where n is the dimensionality of S and k is the dimensionality of S sub • It can also be shown that S null is a valid subspace of S and consequently S sub is also the null space of S null
Page 1 and 2:
DC COURSE FILE
Page 3 and 4:
GEETHANJALI COLLEGE OF ENGINEERING
Page 5 and 6:
Convolution Codes: Encoding, decodi
Page 7 and 8:
III. To inculcate positive attitude
Page 9 and 10:
7. Importance of the course and how
Page 11 and 12:
DC 12: Compute the power and bandwi
Page 13 and 14:
10. Course mapping with PEO’s and
Page 15 and 16:
13.Micro plan : Sl. no Unit No. Tot
Page 17 and 18:
14.Detailed Notes UNIT 1 : Elements
Page 19 and 20:
A communication system may transmit
Page 21:
the wavelength is extremely long, m
Page 25 and 26:
asic elements of digital communicat
Page 27 and 28:
4. Channel introduced many types of
Page 29 and 30:
5. Bandwidth is another scarce reso
Page 35 and 36:
Pulse Code Modulation ‣ PCM gener
Page 37:
77777333333333333333333333333333333
Page 40 and 41:
• The most common technique for s
Page 42 and 43:
Pulse Code Modulation (PCM) : • P
Page 44 and 45:
Figure 3.11 Illustration of the qua
Page 46 and 47: Quantization (nonuniform quantizer)
Page 48 and 49: Time-Division Multiplexing(TDM):
Page 50 and 51: Let m n where T The error signal is
Page 52 and 53: 3. Simplify receiver design Because
Page 54 and 55: Figure 3.27 Block diagram illustrat
Page 56 and 57: Adaptive Differential Pulse-Code Mo
Page 59 and 60: ASK, OOK, MASK: • The amplitude (
Page 61 and 62: Frequency Shift Keying: • One fre
Page 63 and 64: s t Acos 2f ct 3 Acos 2f
Page 65 and 66: QAM and QPR: • QAM is a combinati
Page 67 and 68: Generation and Detection of Coheren
Page 69 and 70: Figure 6.29 Signal-space diagram fo
Page 72 and 73: UNIT 3 Base Band Transmission And O
Page 74 and 75: • The tails of hI(t) decay as 1/|
Page 76 and 77: • precoding d b d k k k2 symbol 1
Page 78 and 79: h( t) N 1 n w n sin c t T b
Page 80 and 81: • Equalization : to compensate fo
Page 82 and 83: e n y n 2E en 2E en 2Eenxnk
Page 84 and 85: - Flexibility - Same H/W may be tim
Page 86 and 87: Interpretation of Eye Diagram:
Page 88 and 89: The set of source symbols is called
Page 90 and 91: We will usually neglect to mention
Page 92 and 93: Note that if Condition1 is satisfie
Page 94 and 95: where dmin is the minimum Hamming d
Page 98 and 99: • S null can be represented by it
Page 100 and 101: G 1 0 I | P 0 0 0 1 0 0 0 0
Page 102 and 103: • Compared with the systematic co
Page 104 and 105: Convolutional Codes ◊ The encoder
Page 106 and 107: Convolution Codes ‣ Encoding, ‣
Page 108 and 109: x m m ''' j j 2 j Here each messa
Page 110: Representing convolutional codes: C
Page 113 and 114: - encoder state diagram for (n,k,L)
Page 115 and 116: • For this reason the non-survive
Page 117 and 118: sequence is 1 1 0 0 0 0 0 (why?). N
Page 119 and 120: Error Correction: • If there is n
Page 121 and 122: correct:1+1+2+2+2=8;8 ( 0.11) 0.88
Page 123 and 124: Motivation: Performance of Turbo Co
Page 125 and 126: Performance as a Function of Number
Page 127 and 128: General Model of Spread Spectrum Sy
Page 129 and 130: Slow and Fast FHSS: • Frequency s
Page 131 and 132: - 10 bit spreading code spreads sig
Page 133 and 134: Direct Sequence Spread Spectrum Usi
Page 135 and 136: 15.Additional Topics: Voice coders
Page 137 and 138: 'Toll Quality' voice coders, such a
Page 139 and 140: The well-known Shannon-Hartley law
Page 141 and 142: its for a known permutation of the
Page 143 and 144: 16. Question papers: B. Tech III Ye
Page 145 and 146: e received code word 110110. Commen
Page 147 and 148:
17. Question Bank 1. (a) State and
Page 149 and 150:
21. A Discrete Memory less Source (
Page 151 and 152:
19. Unit wise Bits CHOOSE THE CORRE
Page 153 and 154:
(d) 5 Answers 1.C 2.D 3.B 4.A 5.C 6
Page 155 and 156:
(b) its capacity gets doubled (c) i
Page 157 and 158:
(d) 6 5. The cascade of two binary
Page 159 and 160:
CHOOSE THE CORRECT ANSWER 1. The mi
Page 161 and 162:
2.C 3.C 4.A 5.D 6.C 7.B 8.B 9.B 10.
Page 163 and 164:
(b) H(X/Y)=1bit/message (c) H(X,Y)=
Page 165 and 166:
(d) log m bits/symbol 6. Theencoder
Page 167 and 168:
3. .Under error free reception, the
Page 169 and 170:
10.B Code No: 56026 Set No. 1 JAWAH
Page 171 and 172:
code No: 56026 Set No. 2 JAWAHARLAL
Page 173 and 174:
B) (Power required)/( Minimum Band
Page 175 and 176:
A) 5 B) 4 C) 2 D) 3 3. Which of the
Page 177 and 178:
Code No: 56026 Set No. 2 JAWAHARLAL
Page 179 and 180:
A) maximum when the source is conti
Page 181 and 182:
Code No: 56026 :2: Set No. 4 II Fil
Page 183 and 184:
Code No: 07A5EC09 Set No. 2 JAWAHAR
Page 185 and 186:
Cont…..2 Code No: 07A5EC09 :2: Se
Page 187 and 188:
8) For the data word 1110 in a (7,
Page 189 and 190:
Page 191 and 192:
a) 0 bits b) 1 bit c) 2 bits d) inf
Page 193 and 194:
Page 195 and 196:
a) increase with its certainty of o
Page 197 and 198:
Code No: 07A5EC09 :2: Set No.4 10)
Page 199 and 200:
Amplitude of 1v.This speech signal
Page 201 and 202:
. Self Information c. Logarithmic m
Page 203 and 204:
75. What are the advantages and dis
Page 205 and 206:
22. Discussion Topics: Data transmi
Page 207 and 208:
Applications and history Data (main
Page 209 and 210:
o o Mesh network Wireless network A
Page 211 and 212:
25. STUDENTS LIST B.TECH III YEAR I
Page 213 and 214:
48 13R11A04L3 M SAI KUMAR 49 14R18A
Page 215 and 216:
Group 8: 36 13R11A04K1 POLISETTY VE
Page 217 and 218:
Unit 2 Pulse-Amplitude Modulation :
Page 219 and 220:
Unit 3 Differential Pulse-Code Modu
Page 221 and 222:
MISSING TOPICS UNIT 1 Hartley's law
Page 223 and 224:
encoding the desired information an
Page 225 and 226:
• f c denotes center frequency
Page 227 and 228:
An interleaver installed between th
Page 229 and 230:
Subject Contents 1.7. 1. Synopsis p
show all

dc

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?