ETSI TS 102 177 V1.5.1 (2010-05)

Technical Specification
Broadband Radio Access Networks (BRAN);
HiperMAN;
Physical (PHY) layer
2 ETSI TS 102 177 V1.5.1 (2010-05)

Reference
RTS/BRAN-0040001r6
Keywords
access, broadband, FWA, HiperMAN, layer 1,
MAN, nomadic, radio
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ETSI
3 ETSI TS 102 177 V1.5.1 (2010-05)
Contents
Intellectual Property Rights . 5
Foreword . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Symbols . 7
3.3 Abbreviations . 8
4 HiperMAN OFDM PHY . 9
4.1 OFDM symbol description . 9
4.2 Transmitted signal . 10
4.3 Channel coding . 12
4.3.1 Randomization . 12
4.3.2 Forward Error Correction (FEC) . 13
4.3.2.1 Concatenated Reed-Solomon / Convolutional Code (RS-CC) . 13
4.3.2.2 Convolutional Turbo Coding (Optional) . 15
4.3.2.2.1 CTC interleaver . 16
4.3.2.2.2 Determination of CTC circulation states . 17
4.3.2.2.3 CTC puncturing . 17
4.3.3 Interleaving . 17
4.3.4 Modulation . 18
4.3.4.1 Data modulation . 18
4.3.4.2 Pilot modulation . 19
4.3.4.3 Rate ID encodings . 20
4.3.5 Example UL RS-CC Encoding . 20
4.3.5.1 Full bandwidth (16 subchannels) . 20
4.3.5.2 Subchannelization (2 subchannels) . 21
4.3.5.3 Subchannelization (1 subchannel) . 22
4.3.6 Preamble structure and modulation . 22
4.3.6.1 Transmission Convergence (TC) sublayer . 25
4.4 Frame structures . 25
4.4.1 PMP . 25
4.4.1.1 Duplexing modes . 25
4.4.1.2 DL frame prefix . 28
4.4.1.3 PMP DL subchannelization zone . 28
4.4.1.4 PMP-AAS zone . 31
4.4.2 Mesh . 34
4.4.3 Frame duration codes . 35
4.5 Control mechanisms . 35
4.5.1 Synchronization . 35
4.5.1.1 Network synchronization . 35
4.6 Ranging . 35
4.6.1 Initial Ranging in AAS systems . 38
4.6.2 Bandwidth requesting . 38
4.6.2.1 Parameter selection . 38
4.6.2.2 Full contention transmission . 40
4.6.2.3 Focused contention transmission . 40
4.6.3 Power control . 41
4.6.3.1 Closed loop power control . 41
4.6.3.2 Open loop power control (optional) . 41
4.7 Transmit diversity space-time coding (optional) . 43
4.7.1 STC 2X2 . 44
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4 ETSI TS 102 177 V1.5.1 (2010-05)
4.7.1.1 STC 2x2 coding . 44
4.7.1.2 STC 2x2 decoding . 45
4.8 Channel quality measurements . 45
4.8.1 Introduction. 45
4.8.2 RSSI mean and standard deviation . 46
4.8.3 CINR mean and standard deviation . 47
4.9 Transmitter requirements . 47
4.9.1 Transmitter channel bandwidth. 48
4.9.2 Transmit power level control . 48
4.9.2.1 Transmitter spectral flatness. 48
4.9.2.2 Transmitter constellation error and test method . 48
4.10 Receiver requirements . 49
4.10.1 Receiver sensitivity . 49
4.10.2 Receiver adjacent and alternate channel rejection . 50
4.10.3 Receiver maximum input signal . 51
4.10.4 Receiver linearity . 51
4.11 Frequency and timing requirements . 51
4.12 Parameters and constants . 51
5 HiperMAN OFDMA PHY . 52
History . 53

ETSI
5 ETSI TS 102 177 V1.5.1 (2010-05)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Broadband Radio Access
Networks (BRAN).
The present document describes the physical layer specifications for High PERformance Radio Metropolitan Area
Network (HiperMAN). Separate ETSI documents provide details on the system overview, Data Link Control (DLC)
layer, Convergence Layers (CL) and conformance testing requirements for HiperMAN. ®
With permission of IEEE (on file as BRAN43d016), portions of the present document are excerpted from
IEEE Standards [2] and [3].
ETSI
6 ETSI TS 102 177 V1.5.1 (2010-05)
1 Scope
The present document specifies the HiperMAN air interface with the specification layer 1 (physical layer), which can be
used to provide Fixed applications, in frequencies below 11 GHz, and Nomadic and converged Fixed-Nomadic
applications, in frequencies below 6 GHz. The present document follows the ISO-OSI model. HiperMAN is confined
only to the radio subsystems consisting of the Physical (PHY) layer and the DLC layer - which are both core network
independent - and the core network specific convergence sub-layer.
For managing radio resources and connection control, the Data Link Control (DLC) protocol is applied, which uses the
transmission services of the DLC layer. Convergence layers above the DLC layer handle the inter-working with layers
at the top of the radio sub-system.
The scope of the present document is as follows:
• It gives a description of the physical layer for HiperMAN systems.
• It specifies the transmission scheme in order to allow interoperability between equipment developed by
different manufacturers. This is achieved by describing scrambling, channel coding, modulation, framing,
control mechanisms, and power control to assist in radio resource management.
• It does cover the receiver and transmitter performance requirements which are specific for HiperMAN
systems.
• Some information clauses and annexes describe parameters and system models to assist in preparing
conformance, interoperability and coexistence specifications.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
[1] ETSI TS 102 178: "Broadband Radio Access Networks (BRAN); HiperMAN; Data Link Control
(DLC) layer".
[2] IEEE 802.16-2004: "IEEE Standard for Local and Metropolitan Area Networks - Part 16: Air
Interface for Fixed Broadband Wireless Access Systems".
[3] IEEE 802.16e-2005: "IEEE Standard for Local and metropolitan area networks - Part 16: Air
Interface for Fixed and Mobile Broadband Wireless Access Systems - Amendment 2: Physical and
Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and
Corrigendum 1".
[4] Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio
equipment and telecommunications terminal equipment and the mutual recognition of their
conformity (R&TTE Directive).
TM
[5] IEEE Std 802.16 -2009: "IEEE Standard for Local and metropolitan area networks Part 16: Air
Interface for Broadband Wireless Access Systems.
ETSI
7 ETSI TS 102 177 V1.5.1 (2010-05)
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Alamouti, S.M.: "A Simple Transmit Diversity Technique for Wireless Communications", IEEE
journal on select areas in communications, Vol.16, No. 8, pages 1451-1458, October 1998.
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Base Station (BS): generalized equipment consisting of one or more Base Station Controllers and one or more Base
Station transceivers
channel coding: sequence composed of three steps; randomizer, forward error correction and interleaving
DL-MAP: structured data sequence that defined the mapping of the DL
DownLink (DL): direction from BS to SS
frequency offset index: index number identifying a particular carrier in an OFDM signal
NOTE: Frequency offset indices may be positive or negative and are counted relative to the DC carrier.
full duplex: equipment that is capable of transmitting and receiving at the same time
guard time: time at the beginning or end of each burst to allow power ramping up and down
half duplex: equipment that cannot transmit and receive at the same time
preamble: sequence of symbols with a given auto-correlation property assisting modem synchronization and channel
estimation
Receive-Transmit Transition Gap (RTG): time to switch from receive to transmit at the BS
Subscriber Station (SS): generalized equipment consisting of a Subscriber Station Controller and Subscriber Station
Transceiver
Transmit-Receive Transition Gap (TTG): time to switch from transmit to receive at the BS
UL MAP: MAC message scheduling UL bursts
UpLink (UL): direction from SS to BS
3.2 Symbols
For the purposes of the present document, the following symbols apply:
BW Nominal channel bandwidth (MHz)
F Sampling frequency (MHz)
sa
N Number of coded bits per OFDM symbol (on allocated subchannels)
cbps
N Nominal size of the FFT operator
FFT
N Number of carriers used to transport either data or pilots within a single OFDM symbol
used
R BW over sampling ratio
os
T Useful OFDM symbol time (s)
b
T Frame duration (ms)
F
ETSI
8 ETSI TS 102 177 V1.5.1 (2010-05)
T OFDM symbol guard time or CP time (s)
g
T OFDM symbol time (s)
s
α Channel measurement averaging constant
avg
Δf Carrier spacing (Hz)
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AAS Adaptive Antenna System
AWGN Average White Gaussian Noise
BER Bit Error Rate
BPSK Binary Phase Shift Keying
BS Base Station
BSID Base Station IDentification
BW BandWidth
CC Convolutional Coding
CCH Control subCHannel
CID Connection IDentifier
CINR Carrier to Interference Noise Ratio
CL Convergence Layer
CNR Carrier to Noise Ratio
CP Cyclic Prefix
CTC Convolutional Turbo Code
DC Direct Current
DCD Downlink Channel Descriptor
DIUC Downlink Interval Usage Code
DL DownLink
DLC Data Link Control
DLFP DownLink Frame Prefix
FCH Frame Control Header
FDD Frequency Division Duplexing
FEC Forward Error Correction
FFT Fast Fourier Transform
HCS Header Check Sequence
H-FDD Half duplex Frequency Division Duplexing
IE Information Element
IFFT Inverse Fast Fourier Transform
LSB least Significant Bit
MAC Media Access Control
MAN Metropolitan Area Network
MSB Most Significant Bit
OFDM Orthogonal Frequency Division Multiplexing
OFDMA Orthogonal Frequency Division Multiple Access
PDU Protocol Data Unit
PHY PHYsical
PMP Point-to-MultiPoint
PRBS Pseudo Random Binary Sequence
PS Physical Slot
QAM Quadrature Amplitude Modulation
QPSK Quadrature Phase Shift Keying
REQ REQuest
RF Radio Frequency
RMS Root Mean Square
RS Reed-Solomon
RS-CC Reed-Solomon / Convolutional Code
RSSI Received Signal Strength Indicator
RTG Receive-Transmit Transition Gap
Rx Receive
ETSI
9 ETSI TS 102 177 V1.5.1 (2010-05)
SNR Signal to Noise Ratio
SS Subscriber Station
SSRTG Subscriber Station Receive Transmit Gap
STC Space Time Coding
TC Transmission Convergence
TDD Time Division Duplexing
TLV Type Length Value
TOs Transmission Opportunities
TTG Transmit-receive Transition Gap
Tx Transmit
UCD Uplink Channel Descriptor
UIUC Uplink Interval Usage Code
UL UpLink
XOR eXclusive OR
4 HiperMAN OFDM PHY
4.1 OFDM symbol description
An OFDM waveform is created by applying an Inverse-Fourier-transform to the source data. The resultant time
duration is referred to as the useful symbol time T . A copy of the last T μs of the useful symbol period, termed
b
g
Cyclic Prefix (CP), is prepended to enable the collection of multipath at the receiver, without loss of orthogonality
between the tones. The resulting waveform is termed the symbol time T . Figure 1 illustrates this structure.
s
Copy samples
Tg T
b
T
s
Figure 1: OFDM symbol time structure
The transmitter energy increases with the length of the CP while the receiver energy remains the same (the CP is
discarded), so there is a 10log (1− T /(T + T )) / log(10) dB loss in SNR. Using the CP, the samples required for
g b g
performing the FFT at the receiver can be taken anywhere over the length of the extended symbol. This provides
multipath immunity as well as a tolerance for symbol time synchronization errors.
On system initialization, the Base Station (BS) CP fraction (T / T ) shall be set to a specific value for use on the
g b
Downlink (DL). Once the BS is operational the CP value shall not be changed. On initialization, the
Subscriber Station (SS) shall search all possible values of CP until it finds the CP being used by the serving BS. The SS
shall use the same CP values determined in DL for the UL. Changing the CP value parameter at the BS through
(re)initialization forces all SS registered on that BS to re-synchronize.
In the frequency domain, each OFDM symbol is comprised of multiple carriers (see figure 2), which belong to one of
three types:
• Data carriers - for data transmission.
• Pilot carriers - for channel estimation and other purposes.
• Null carriers - for guard bands and the DC carrier.
ETSI
10 ETSI TS 102 177 V1.5.1 (2010-05)
Guard
Pilot DC Data Guard
band
carriers carrier carriers band

Channel
Figure 2: OFDM symbol frequency structure
4.2 Transmitted signal
Equation 1 specifies the transmitted signal voltage s(t) to the antenna, as a function of time, during any OFDM symbol.
⎧ ⎫
⎪ k =N / 2 ⎪
used
2 jπkΔf()t−T
⎪ ⎪
2 jπf t g
c
s(t) = Re e c × e
⎨ ⎬ (1)
k
∑
⎪ ⎪
k=−N / 2
used
⎪ ⎪
k≠0
⎩ ⎭
where: t is the time elapsed since the beginning of the subject OFDM symbol, with 0< s
C is a complex number; the data to be transmitted on the carrier whose frequency offset index is k , during
k
the subject OFDM symbol. It specifies a point in a Quadrature Amplitude Modulation (QAM) constellation.
In the case of subchannelization, C is zero for all unallocated.
k
f is the RF carrier frequency, being the centre frequency of the intended RF frequency channel.
c
k is the frequency offset index.
The parameters of the transmitted OFDM signal, which shall be used, are given in table 1.
ETSI
11 ETSI TS 102 177 V1.5.1 (2010-05)
Table 1: OFDM symbol parameters
Parameter Value
N
FFT
N 200
used
T
g
T 1/4, 1/8, 1/16, 1/32
b
Frequency offset indices of guard carriers -128, -127 to -101
+101, +102 to 127
Frequency offset indices of Pilots -88, -63, -38, -13, 13, 38, 63, 88
Subchannel Index Allocated frequency offset indices of carriers

0b00001 {-100:-98, -37:-35, 1:3, 64:66}

0b00010 {-38}
0b00100 0b00011 {-97:-95, -34:-32, 4:6, 67:69}
0b00101 {-94:-92, -31:-29, 7:9, 70:72}
0b00110 {13}
0b01000  0b00111 {-91:-89, -28:-26, 10:12, 73:75}
{-87:-85, -50:-48, 14: 16, 51:53}
0b01001
0b01010 {-88}
0b01100 0b01011 {-84,-82, -47:-45, 17: 19, 54:56}
0b01101 {-81:-79, -44:-42, 20:22, 57:59}
0b01110 {63}
0b10000  0b01111 {-78:-76, -41:-39, 23:25, 60:62}
0b10001 {-75:-73, -12:-10, 26:28, 89:91}
0b10010 {-13}
0b10100 0b10011 {-72:-70, -9: -7, 29:31, 92:94}
0b10101 {-69:-67, -6: -4, 32:34, 95:97}
0b10110 {38}
0b11000  0b10111 {-66:-64, -3: -1, 35:37, 98:100}
0b11001 {-62:-60, -25:-23, 39:41, 76:78}
0b11010 {-63}
0b11100 0b11011 {-59:-57, -22:-20, 42:44, 79:81}
0b11101 {-56:-54, -19:-17, 45:47, 82:84}
0b11110 {88}
0b11111 {-53:-51, -16:-14, 48:50, 85:87}

NOTE: Pilot carriers are allocated only if two or more subchannels are allocated.

ETSI
12 ETSI TS 102 177 V1.5.1 (2010-05)
Using the parameters as specified in table 1, the following relationships shall hold.
F = floor (R × BW / 8 000 ) × 8 000
sa os
R × BW
os
Δf =
N
FFT
T =
b
Δf
⎛T ⎞
g
T = ×T
⎜ ⎟
g b
T
b
⎝ ⎠
T = T + T
s b g
T =
sa
F
sa
F = R × BW
sa os
4.3 Channel coding
Channel coding is composed of three steps: randomization, forward error correction, and interleaving. They shall be
applied in this order at transmission. The complementary operations shall be applied in reverse order at reception.
4.3.1 Randomization
Data randomization is performed independently on each burst of uplink and downlink data (i.e. not on pilots and
preambles) on the subchannels in the frequency domain and OFDM symbols in the time domain. If the amount of data
to transmit does not fit exactly the amount of data allocated, padding of 0xFF ("1"s only) shall be added to the end of
the transmission block for the unused integer number of bytes, up to the amount of data allocated. For RS-CC and CC
encoded data, padding will be added to the end of the transmission block, up to the amount of data allocated minus one
byte, which shall be reserved for the introduction of a 0x00 tail byte by the FEC. For CTC, if implemented, padding will
be added to the end of the transmission block, up to the amount of data allocated.
The Pseudo Random Binary Sequence (PRBS) generator shall be 1++x x as shown in figure 3. Each data byte to
be transmitted shall enter sequentially into the randomizer, most significant bit (MSB) first. The seed value shall be
used to calculate the randomization bits, which are combined in an XOR operation with the serialized bit stream of each
burst. The "data out" bits from the randomizer shall be applied to the FEC.

lsb msb
2 3 4 5 6 7 8 9 10 11 12 13 14 15

Data out
Data in
Figure 3: Data randomization PRBS
On the DL, the randomizer shall be re-initialized at the start of the FCH and at the start of the STC zone only in the case
a FCH-STC is present, with the vector: 1 0 0 1 0 1 0 1 0 0 0 0 0 0 0. The randomizer shall not be reset at the start of the
burst immediately following FCH or FCH-STC. At the start of subsequent bursts the randomizer shall be initialized
with the vector shown in figure 4. The OFDM symbol number (i.e. the number of the first OFDM symbol of the data
burst) shall be counted from the start of the DL-subframe, the first symbol being counted as symbol #0.
ETSI
13 ETSI TS 102 177 V1.5.1 (2010-05)
For a DL subchannelization zone the randomizer is initialized in an equivalent manner. At the start of the DL
subchannelized zone, the randomizer shall be re-initialized to the sequence 1 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0. The
randomizer shall not be reset at the start of the first burst in the CCH. At the start of subsequent bursts, the randomizer
shall be initialized with the vector shown in figure 4. The frame number used for initialization refers to the frame in
which the subchannelized burst is transmitted and can be obtained from the SBCH_DLFP (refer to table 12).
BSID UIUC Frame number
msb b b b b b b b b b b b b lsb
3 2 1 0 3 2 1 0 3 2 1 0
lsb b b b b 1 1 b b b b 1 b b b b msb
3 7 11
0 1 2 6 8 5 12 13 14
Figure 4: Scrambler DL initialization vector for bursts #2 to N
On the UL, the randomizer shall be initialized with the vector shown in figure 5. The frame number used for
initialization is that of the frame in which the UL map that specifies the uplink burst was transmitted.

BSID UIUC Frame number
msb lsb
b b b b b b b b b b b b
3 2 1 0 3 2 1 0 3 2 1 0
lsb b b b b 1 1 b b b b 1 b b b b msb
0 1 2 3 6 7 8 9 11 12 13 14
Figure 5: Scrambler UL initialization vector
4.3.2 Forward Error Correction (FEC)
The FEC consisting of the concatenation of a Reed-Solomon outer code and a rate-compatible convolutional inner code
shall be supported on both UL and DL. Support of Convolutional Turbo Code (CTC) is optional. The most robust burst
profile shall always be used as the coding mode when requesting access to the network and in the Frame Control
Header (FCH) burst.
The encoding is performed by first passing the data in block format through the RS encoder and then passing it through
a convolutional encoder. Eight tail bits are introduced at the end of each allocation, which are set to zero. This tail Byte
shall be appended after randomization. In the RS encoder, the redundant bits are sent before the input bits, keeping the
tail bits at the end of the allocation. When the total number of data bits in a burst is not an integer number of Bytes, zero
pad bits are added after the zero tail bits. The zero pad bits are not randomized. Note that this situation can occur only in
subchannelization. In this case the RS encoding is not employed.
4.3.2.1 Concatenated Reed-Solomon / Convolutional Code (RS-CC)
The RS encoding shall be derived from a systematic RS (N = 255, K = 239, T = 8) code using GF(2 ), where:
N is the number of overall bytes after encoding.
K is the number of data bytes before encoding.
T is the number of data bytes which can be corrected.
For the systematic code, the code generator polynomial g(x) , shown in equation 2, and field generator polynomial
p(x) , shown in equation 3, shall be used.
0 1 2 2T −1
g(x) = (x + λ )(x + λ )(x + λ ) to (x + λ ), λ = 02 (2)
HEX
8 4 3 2
1p(x) = x + x + x + x + (3)
ETSI
14 ETSI TS 102 177 V1.5.1 (2010-05)
This code is shortened and punctured to enable variable block sizes and variable error-correction capability. When a
block is shortened to K' data bytes, add 239 - K' zero bytes as a prefix. After encoding discard these 239 - K' zero bytes.
When a codeword is punctured to permit T' bytes to be corrected, only the first 2T' of the total 16 parity bytes shall be
employed. The bit/byte conversion shall be MSB first.
Each RS block is encoded by the binary convolutional encoder, which shall have native rate of 1/2, a constraint length
equal to 7, and shall use the generator polynomials codes shown in equation 4 to derive its two code bits.
G = 171 for X
1 OCT
(4)
G = 133 for Y
2 OCT
The generator is depicted in figure 6.

X
1 bit 1 bit 1 bit 1 bit 1 bit 1 bit
Data in
delay delay delay delay delay delay

Y
Figure 6: Convolutional encoder of rate 1/2
Puncturing patterns and serialization order which shall be used to realize different code rates are defined in table 2.
Transmitted bits are denoted by "1" and removed bits are denoted by "0". X and Y are in reference to figure 6.
Table 2: The inner convolutional code puncturing configuration
Code rate d X Y Order
free
1/2 10 1 1 X Y
1 1
2/3 6 10 11 X Y Y
1 1 2
3/4 5 101 110 X Y Y X
1 1 2 3
5/6 4 10101 11010 X Y Y X Y X
1 1 2 3 4 5
The encoding is performed by first passing the data in block format through the RS encoder and then passing it through
a convolutional encoder. A single tail 0x00 tail byte is appended to the end of each burst. This tail byte shall be
appended after randomization. In the RS encoder, the redundant bits are sent before the input bits, keeping the 0x00 tail
byte at the end of the allocation. To ensure that the number of bits after the convolutional encoder is divisible by N ,
cbps
as specified in table 7, zero (0b0) pad bits added after the zero tail bits before the encoder. The zero bits are not
randomized. Note that this situation can occur only in the subchannelization. In this case, the RS encoding is not
employed.
Table 3 defines the block sizes for the different modulation levels and code rates. As 64-QAM is optional for license
exempt bands, the codes for this modulation shall only be implemented if the modulation is implemented.
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15 ETSI TS 102 177 V1.5.1 (2010-05)
Table 3: Mandatory channel encodings
Modulation Uncoded block size Coded block Overall coding rate RS code CC code rate
(bytes) size (bytes)
BPSK 12 24 1/2 (12,12,0) 1/2
QPSK 24 48 1/2 (32,24,4) 2/3
QPSK 36 48 3/4 (40,36,2) 5/6
16-QAM 48 96 1/2 (64,48,8) 2/3
16-QAM 72 96 3/4 (80,72,4) 5/6
64-QAM 96 144 2/3 (108,96,6) 3/4
64-QAM 108 144 3/4 (120,108,6) 5/6

Table 3 gives the block sizes and code rates for the different modulation and code rates. Since 64-QAM is optional for
license-exempt bands, these codes are only implemented if the option is implemented.
When subchannelization is applied in the UL, the FEC shall bypass the RS encoder and use the Overall Coding Rate as
indicated in table 3 as CC Code Rate. The Uncoded Block Size and Coded Block Size may be computed by multiplying
the values listed in table 3 by the number of allocated subchannels divided by 16. In the case of BPSK modulation,
RS encoder should be bypassed.
In the case of BPSK modulation, the RS coder should be bypassed.
4.3.2.2 Convolutional Turbo Coding (Optional)
The Convolutional Turbo Code encoder, including its constituent encoder, is depicted in figure 7. It uses a double
binary Circular Recursive Systematic Convolutional code. The bits of the data to be encoded are alternately fed to A
and B, starting with the MSB of the first byte being fed to A. The encoder is fed by blocks of k bits or N couples
(k = 2 × N bits). For all the frame sizes k is a multiple of 8 and N is a multiple of 4. Further N shall be limited to:
8 ≤ N / 4 ≤ 1 024 . For subchannelization, the coding block size is limited to blocks at least 48 bits in length, and no
more than 1 024 bits in length. In addition, k cannot be a multiple of 7.
The polynomials defining the connections are described in octal and symbol notations as follows:
• for the feedback branch: 0×B, equivalently 1 + D + D (in symbolic notation);
2 3
• for the Y parity bit: 0×D, equivalently 1 + D + D .
A
B
Constituent C Y
CTC 1 1
encoder Puncturing
Interleaver 2 C Y
2 2
switch
D D D
+ + +
Y
+
Constituent encoder
Figure 7: CTC encoder
First, the encoder (after initialization by the circulation state Sc , see below) is fed the sequence in the natural order
(position 1) with the incremental address i = 0 to N-1. This first encoding is called C encoding. Then the encoder (after
initialization by the circulation state Sc , see below) is fed by the interleaved sequence (switch in position 2) with
incremental address j = 0 to N-1. This second encoding is called C encoding.
ETSI
16 ETSI TS 102 177 V1.5.1 (2010-05)
The order in which the encoded bit shall be fed into the interleaver (see clause 4.3.3) is:
A , B to A , B , Y , Y to Y , Y , Y to Y ,
0 0 N-1 N-1 1,0 1,1 1,M 2,0 2,1 2,M
where M is the number of parity bits.
Table 4 gives the block sizes, code rates, channel efficiency, and code parameters for the different modulation and
coding schemes. As 64-QAM is optional for license exempt bands, the codes for this modulation shall only be
implemented if the modulation is implemented. N denotes the number of subchannels of the allocation in which the
sub
encoded data will be transmitted. The data block size in bytes per OFDM symbol may be calculated as N/4. Further,
P equals 3N/4.
Table 4: Optional CTC Coding per Modulation
Modulation Overall Code N P
Rate
QPSK 1/2 6 × N 7
sub
QPSK 2/3 8 × N 11
sub
QPSK 3/4 9 × N 17
sub
16-QAM 1/2 12 × N 11
sub
16-QAM 3/4 18 × N 13
sub
64-QAM 2/3 24 × N 17
sub
64-QAM 3/4 27 × N 17
sub
In table 4, N denotes the number of subchannels of the allocation in which the encoded data will be transmitted.
sub
The data block size (in Bytes per OFDM symbol) may be calculated as N/4. Further, P equals 3N/4.
4.3.2.2.1 CTC interleaver
The interleaver requires the parameters P , shown in table 4, and P .
0 1
The two-step interleaver shall be performed by:
Step 1: Switch alternate couples
for j = 1 to N
if ( j == 0) let (B, A) = (A, B) (i.e. switch the couple)
mod
Step 2: P (j)
i
The function P (j) provides the interleaved address i of the consider couple j.
i
for j = 1 to N
switch j :
mod
- case 0: i = (P × j +1)
0 mod
N
- case 1: iP=×(1j++N/4+P)
01mod
N
- case 2: i = (P × j +1+ P )
0 1 mod
N
- case 3: i = (P × j +1+ N / 2 + P )
0 1 mod
N
ETSI
17 ETSI TS 102 177 V1.5.1 (2010-05)
4.3.2.2.2 Determination of CTC circulation states
The state of the encoder is denoted S (0 ≤ S ≤ 7) with S the value read binary (left to right) out of the constituent
encoder memory (see figure 7). The circulation states Sc and Sc are determined by the following operations:
1 2
1) initialize the encoder with state 0. Encode the sequence in the natural order for the determination of Sc1 or in
the interleaved order for determination of Sc . In both cases the final state of the encoder is S0 ;
2 N-1
2) according to the length N of the sequence, use table 5 to find Sc or Sc .
1 2
Table 5: Circulation state lookup table (Sc)
S0N-1
N
mod
0 1 2 3 4 5 6 7
1 0 6 4 2 7 1 3 5
2 0 3 7 4 5 6 2 1
3 0 5 3 6 2 7 1 4
4 0 4 1 5 6 2 7 3
5 0 2 5 7 1 3 4 6
6 0 7 6 1 3 4 5 2
4.3.2.2.3 CTC puncturing
The three code-rates are achieved through selectively deleting the parity bits (puncturing). The puncturing patterns are
identical for both codes C and C .
1 2
Table 6: Circulation state lookup table (Sc)
Rate Y
R /(R +1)
0 1 2 3 4 5
n n
1/2 1 1
2/3 1 0 1 0
3/4 1 0 0 1 0 0
4.3.3 Interleaving
A block interleaver shall interleave all encoded data bits with a block size corresponding to the number of coded bits
per the allocated subchannels per OFDM symbol, N . The interleaver is defined by a two step permutation. The
cbps
first, shown in equation 5, ensures that adjacent coded bits are mapped onto nonadjacent subcarriers. The second
permutation, shown in equation 6, ensures that adjacent coded bits are mapped alternately onto less or more significant
bits of the constellation, thus avoiding long runs of less reliable bits.
Let N be the number of coded bits per subcarrier, i.e. 1, 2, 4 or 6 for BPSK, QPSK, 16-QAM or 64-QAM,
cpc
respectively. Let s = ceil(N 2) . Within a block of N bits at transmission, let k be the index of a coded bit before
cpc
cbps
the first permutation; mk be the index of that coded bit after the first and before the second permutation; and let jk be the
index of that coded bit after the second permutation, just prior to modulation mapping.
The first permutation is defined by the formula:
m=+N 12 k mod 12 floor k 12 1k = 0,1, to, N − (5)
() ()
()
k cbps cbps
The second permutation is defined by the formula:
j = s × floor()m / s + (m + N − floor(12 × m / N ))mod(s) 1k = 0,1, to, N − (6)
k k k cbps k cbps cbps
ETSI
18 ETSI TS 102 177 V1.5.1 (2010-05)
The de-interleaver, which performs the inverse operation, is also defined by two permutations. Within a received block
of N bits, let j be the index of a bit before the first permutation; let m be the index of that bit after the first and
cbps j
before the second permutation; and let k be the index of that bit after the second permutation, just prior to delivering the
j
block to the convolutional decoder.
The first permutation is defined by the rule formula:
m = s × floor()j / s + (j + floor(12 × j / N ))mod(s) 1j = 0,1, to, N − (7)
j cbps cbps
The second permutation is defined by the rule formula:
kj=−12mj N −1 floor 12mj N 1j = 0,1, to, N − (8)
()()
cbps cbps cbps
The first permutation in the de-interleaver is the inverse of the second permutation in the interleaver, and conversely.
table 7 shows the bit interleaver sizes as a function of modulation and coding. The first bit of the interleaver shall map
to the MSB in the constellation.
Table 7: Block sizes of bit interleaver

N
cbps
Default 8 subchannels 4 subchannels 2 subchannels 1 subchannel
(16 subchannels)
BPSK 192 96 48 24 12
QPSK 384 192 96 48 24
16-QAM 768 384 192 96 48
64-QAM 1 152 576 288 144 72
4.3.4 Modulation
4.3.4.1 Data modulation
After bit interleaving, the data bits are entered serially to the constellation mapper. BPSK, Gray-mapped QPSK,
16-QAM, and 64-QAM as shown in figure 8 shall be supported. Support of 64-QAM is optional for unlicensed bands.
The constellations as shown in figure 8 shall be normalized by multiplying the constellation point with the indicated
factor c to achieve equal average power. For each modulation, b denotes the LSB. The first bit out of the interleaver
shall be mapped to the MSB and so forth.
Per-allocation adaptive modulation and coding shall be supported in the DL. The UL shall support different modulation
schemes for each SS based on the Media Access Control (MAC) burst configuration messages coming from the BS.
The constellation-mapped data
...