`
`r
`
`‘
`
`.
`
`. Mw.m........m..,.~....‘....—r....(.....e..-e,
`
`"hrs:/?rc ‘sue
`Released by : ETSI/PT 12
`, Release date: February 1992
`
`RELEASE NOTE
`
`Recommendation (3811 06.10
`
`(Release 92, Phase 1)
`
`GSM Full Rate Speech Transcoding
`
`VPrevious1y distributed version
`New Released version February 92
`
`(Release 1/90)
`
`1. RS850}!
`
`fO1‘ 611311965
`
`No changes since the previously distributed version.
`
`Notice: This material may be
`
`protected by copyright law
`
`(Title 17 U.S. Code)
`
`MW .
`
`.
`
`RPX Exhibit 1012
`RPX Exhibit 1012
`RPX v. DAE
`RPX V. DAE
`
`RPXExNbfl1012-Page1
`RPX Exhibit 1012 - Page 1
`
`
`
`Ȏ
`
`\
`
`Ears:/Gsm '
`
`’
`
`Version 3.2.0
`
`GSM recommendation: 06.10
`
`Title: GSM full rate speech transcoding
`
`gate: February 1992
`
`List 0: contents: 1. General
`
`2. Transmission characteristics
`
`3. Functional description of the RPE-LTP codec
`
`4. Computational details of the RPE-LTP codec
`
`5. Digital test sequences
`
`Annex 1. Codec performance
`
`Annex 2. Subjective relevance of the speech
`coder output bits
`
`Annex 3. Format for test sequence distribution
`
`NOTE: This Recommendation is a reproduction of recommendationi
`T/L/03/11 "13 kbit/s Regular Pulse Excitation - Long Term s
`Prediction - Linear Predictive Coder for use in the
`Pan-European Digital Mobile Radio System".
`
`Floppy disks containing the digital test sequences described
`in section 5 can be distributed by ETSI Secretariat on request.
`
`RPX Exhibit 1012 - Page 2
`RPX Exhibit 1012 - Page 2
`
`
`
`ETSI/GSM
`
`.
`
`Version 3.2:0
`
`A The Contact information of the ETSI secretariat is:
`
`ETSI
`
`B.P. 152
`
`F 06561 Valbonne Cedex
`
`France
`
`‘ Tel
`
`+33 92 94 42 00
`
`Fax
`
`+33 93 65 47 16
`
`Language 0; or;gina1: English
`
`Number of pages: 93
`
`RPXExmbH1012-Page3
`RPX Exhibit 1012 - Page 3
`
`
`
`viz
`
`BT51/GSM
`
`GSM 06.10 / page 3
`
`Version 3.2.0
`
`Detailed list of contents
`~J:'k~k*'k***‘k********'k***'k**~k
`
`E S
`
`I-‘I-‘F-‘I-‘I-‘|—’l-’
`
`\10\L!1I3=-LUBJ}-‘
`
`COPE
`OUTLINE DESCRIPTION
`FUNCTIONAL DESCRIPTION OF AUDIO PARTS
`PCM FORMAT CONVERSION
`PRINCIPLES OF THE RPE-LTP ENCODER
`PRINCIPLES OF THE RPE-LTP DECODER
`SEQUENCE AND SUBJECTIVE IMPORTANCE OF ENCODED PARAMETERS
`
`2- IEAH$Ml£SlQH.Q§ABAQIE3ISII§£
`
`2.1. PERFORMANCE CHARACTERISTICS OF THE ANALOGUE/DIGITAL
`INTERFACES
`
`2.2. TRANSCODER DELAY
`
`3. FQNQTLQEAL Q§§g3IP2IQfl QF THE RPE-LTP QQDEQ
`
`FUNCTIONAL DESCRIPTION OF THE RPE-LTP ENCODER
`
`l Offset compensation
`2. Preemphasis
`3 Segmentation
`.4. Autocorrelation
`5. Schur Recursion
`6. Transformation of reflection coefficients to Log.—Area
`Ratios
`. Quantization and coding of Log.—Area Ratios
`Decoding of the quantized Log.-Area Ratios
`. Interpolation of Log.—Area Ratios
`. 0. Tranformation of Log.—Area Ratios into reflection
`coefficients
`Short term Analysis Filtering
`. Sub—segmentation
`.l.13. Calculation of the LTP parameters
`Coding/Decoding of the LTP lags
`Coding/Decoding of the LTP gains
`Long term analysis filtering
`. Long term synthesis filtering
`. Weighting Filter
`Adaptive sample rate decimation by RPE grid selection
`APCM quantization of the selected RPE sequence
`APCM inverse quantization
`RPE grid positioning
`
`.
`
`F-'
`
`F-' O\
`
`.
`
`b~JL».JL»JUJlaJU)L».)LA)l.«JL:JLAD(.~)
`
`~
`
`RPXExNbfl1012-Page4
`RPX Exhibit 1012 - Page 4
`
`
`
`yi
`
`ETSI/GSM
`
`GSM 06.10 / page 4
`
`Version 3.2.0
`
`.2. DECODER
`
`1. RPE decoding section
`.2. Long Term Prediction section
`Short term synthesis filtering section
`. Postprocessing
`
`34
`
`.1. DATA REPRESENTATION AND ARITHMETIC OPERATIONS
`.2. FIXED POINT IMPLEMENTATION OF THE RPE-LTP CODER
`
`o
`
`o
`a
`
`Scaling of the input variable
`Downscaling of the input signal
`Offset compensation
`Preemphasis
`Autocorrelation
`Computation of the reflection coefficients
`Transformation of reflection coefficients to Log.—Area
`Ratios
`Quantization and coding of the Log.-Area Ratios
`Decoding of the coded Log.-Area Ratios
`Computation of the quantized reflection coefficients
`
`[U1-‘
`
`to get the LARp[1.,8]
`. Interpolation of the LARpp[1..8]
`. Computation of the rp[1..8] from the interpolated
`LARp[1..8]
`
`o
`
`0o
`
`KDKO\O(X)\1O'\Ll'I|¥>UJ£\JI—‘O
`
`
`LawIxaiuiuEuummmuw
`
`sbnbshobtbahobubvb.....t\)[\)t\!t\JI\Jl\)t\Jt\>t\)».0.I-‘I-‘I-'1-‘I-‘F-‘!-’#-'9-I®\luh
`
`0 Short
`term analysis filtering
`l-‘
`. Calculation of the LTP parameters
`Long term analysis filtering
`. Weighting filter
`RPE grid selection
`. APCM quantization of the selected RPE sequence
`APCM inverse quantization
`RPE grid positioning
`. Update of the reconstructed short term residual signal
`dp[-120..-1]
`
`N L
`
`u)
`
`.
`
`U1
`U1
`
`4 3
`
`FIXED POINT IMPLEMNTATION OF THE RPE-LTP DECODER
`
`4 3 1. RPE decoding section
`4 3 2. Long term synthesis filtering
`4 3 3. Computation of the decoded reflection coefficients
`4.3.4. Short
`term synthesis filtering section
`4 3 S. Deemphasis filtering
`4 3 6. Upscaling of the output signal
`4 3 7 Truncation of the output variable
`
`4 4
`
`TABLES USED IN THE FIXED POINT IMPLEMENTATION OF THE RPE—LTP
`CODER AND DECODER
`
`RPXExmbH1012-Page5
`RPX Exhibit 1012 - Page 5
`
`
`
`ETSI/GSM
`
`osm 05.10 / page 5
`
`Version 3.2.0
`
`5- DI§IIAL_2§£I_S§QEENQES
`
`INPUT AND OUTPUT SIGNALS
`5.1.
`5.2. CONFIGURATION FOR THE APPLICATION OF THE TEST SEQUENCES
`
`5
`5.
`
`5
`
`1. Configuration 1
`.2. Configuration 2
`
`(encoder only)
`(Decoder only)
`
`TEST SEQUENCES
`
`.1. Test sequences for configuration 1
`2. Test sequences for configuration 2
`
`ANNEX 1- QQ2§Q_2EB£QBMAHQ§
`
`INTRODUCTION
`Al.l.
`A1.2. SPEECH PERFORMANCE
`
`A1.2.l. Single encoding
`A1.2.2. Speech performance when interconnected with coding systems
`on an analogue basis
`
`A1.2.2.1.
`Performance with 32 kbit/s ADPCM (G.'72l)
`A1.2.2.2. Performance with another RPE—LTP codec
`A1.2.2.3. Performance with encoding other than RPE-LTP and 32
`kbit/S ADPCM (G.72l)
`
`Al.3. NON—SPEECH PERFORMANCE
`
`A.l.3.l. Performance with single sine waves
`A1.3.2. Performance with DTMF tones
`Al.3.3. Performance with information tones
`A1.3.4. Performance with voice—band data
`
`Al.4. DELAY
`A1.5. REFERENCES
`
`ANNEX 2.
`
`REL V
`
`F THE
`
`D R
`
`T
`
`I
`
`ANNEX 3. EQBMAI E93 TEST SEQQENQE QISTRIBQTIQH
`
`A3.1. TYPE OF FILES PROVIDED
`A3.2. FILE FORMAT DESCRIPTION
`
`RPXExmbH1012-Page6
`RPX Exhibit 1012 - Page 6
`
`
`
`v---m...~.c.,............,..........................
`
`,
`
`,
`
`,
`
`ETSI/GSM
`
`GSM 06.10 / page 6
`
`Version 3.2.0
`
`1. GENERAL
`
`The transcoding procedure specified in this recommendation is
`applicable for the full-rate traffic channel
`(TCH)
`in the Pan-
`‘ European Digital Mobile Radio (DMR) system. The use of this
`transcoding scheme for other applications has not been considered.
`
`In recomendation GSM 06.01, a reference configuration for the
`speech transmission chain of the Pan-European DMR system is shown.
`According to this reference configuration,
`the speech encoder
`takes its input as a 13 bit uniform PCM signal either from the
`audio part of the mobile station or on the network side,
`from the
`PSTN via an 8 bit/A—law to 13 bit uniform PCM conversion. The
`encoded speech at the output of the speech encoder is delivered to
`a channel encoder unit which is specified in Rec.GSM 05.03. In.the
`receive direction,
`the inverse operations take place.
`
`This recomendation describes the detailed mapping between input
`blocks of 160 speech samples in 13 bit uniform PCM format to
`encoded blocks of 260 bits and from encoded blocks of 260 bits to
`output blocks of 160 reconstructed speech samples.
`The sampling
`rate is 8000 sample/s leading to an average bit rate for the
`encoded bit stream of 13 kbit/s. The coding scheme is the
`so—called Regular Pulse Excitation — Long Term prediction — Linear
`Predictive Coder, here-after referred to as RPE-LTP.
`
`-
`
`The recommendation also specifies the conversion between A-law PCM
`and 13 bit uniform PCM. Performance requirements for the audio
`input and output parts are included only to the extent that they
`affect the transcoder performance. The recomendation also
`describes the codec down to the bit level,
`thus enabling the
`verification of compliance to the recomendation to a high degreep
`of confidence by use of a set of digital test sequences. These
`test sequences are also described and are available on floppy
`disks.
`
`1.2. OUTLINE DESCRIPTION
`
`The recommendation is structured as follows:
`
`Section 1.3 contains a functional description of the audio parts
`including the A/D and D/A functions. Section 1.4 describes the
`conversion between 13 bit uniform and 8 bit A—law samples.
`Sections 1.5 and 1.6 present a simplified description of the
`principles of the RPE—LTP encoding and decoding process
`respectively. In section 1.7,
`the sequence and subjective
`importance of encoded parameters are given.
`
`RPX Exhibit 1012 - Page 7
`RPX Exhibit 1012 - Page 7
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 7
`
`Version 3.2.0
`
`Section 2 deals with the transmission characteristics of the audio
`parts that are relevant for the performance of the RPE£LTP codec.
`some transmission characteristics of the RPE-LTP codec are also
`specified in section 2. section 3 presents the functional descrip-
`tion of the RPE—LTP coding and decoding procedures, whereas
`section 4 describes the computational details of the algorithm.
`Procedures for the verification of the correct functioning of the
`RPE—LTP are described in section 5.
`
`Performance and network aspects of the RPE—LTP codec are contained
`-in annex 1.
`
`1.3. FUNCTIONAL DESCRIPTION OF AUDIO PARTS
`
`The analogue—to—digital and digital—to-analogue conversion will in
`principle comprise the following elements:
`
`1) Analogue to uniform digital
`
`— microphone,
`— input level adjustment device,
`-
`— input anti-aliasing filter,
`— sample—hold device sampling at 8 kHz,
`— analogue—to—uniform digital conversion to 13 bits
`representation.
`
`The uniform format shall be represented in two's complement.
`
`2) Uniform digital to analogue
`
`— conversion from 13 bit /8kHz uniform PCM to analogue,
`- a hold device,
`— reconstruction filter including X/sin x correction,
`- output level adjustment device,
`— earphone or loudspeaker.
`
`In the terminal equipment,
`
`the A/D function may be achieved either
`
`— by direct conversion to 13 bit uniform PCM format.
`- or by conversion to 8 bit/A-law companded format, based on a
`standard A-law codec/filter according to CCITT rec.
`G.7l1/714,
`followed by the 8-bit to 13-bit conversion
`according to the procedure specified in section 1.4.
`
`For the D/A operation,
`
`the inverse operations take place.
`
`In the latter case it should be noted that the specifications in
`CCITT recomendation G.7l4 are concerned with PCM equipment
`located in the central parts of the network. When used in the
`terminal equipment,
`this specification does not on its own ensure
`sufficient out-of—band attenuation.
`
`RPX Exhibit 1012 - Page 8
`RPX Exhibit 1012 - Page 8
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 8
`
`Version 3.2.0
`»w:
`
`The specification of out-of—band signals is defined in section 2
`between the acoustic signal and the digital interface to take into
`account that the filtering in the terminal can be achieved both by
`electronic and acoustical design.
`
`1.4. PCM FORMAT CONVERSION
`
`I The conversion between 8 bit A-law companded format and the 13-bit
`uniform format shall be as defined in CCITT Recommendation G.72l,
`section 4.2.1, sub-block EXPAND and section 4.2.7,
`sub—block
`COMPRESS. The parameter LAW = 1 should be used.
`
`1.5. PRINCIPLES OF THE RPE-LTP ENCODER
`
`A simplified block diagram of the RPE—LTP encoder is shown in Fig“
`1.1. In this diagram the coding and quantization functions are not
`shown explicitly.
`—
`
`The input speech frame, consisting of 160 signal samples (uniform
`13 bit PCM samples),
`is first pre—processed to produce an
`offset—free signal, which is then subjected to a first order
`pre-emphasis filter. The 160 samples obtained are then analyzed to
`determine the coefficients for the short term analysis filter (LPC
`analysis). These parameters are then used for the filtering of
`the same 160 samples. The result is 160 samples of the short term
`residual signal. The filter parameters,
`termed reflection
`coefficients, are transformed to log.area ratios, LARs, before
`transmission.
`
`the speech frame is divided into 4
`For the following operations,
`sub—frames with 40 samples of the short term residual signal in
`each. Each sub—frame is processed blockwise by the subsequent
`functional elements.
`
`“
`
`Before the processing of each sub—block of 40 short term residual
`samples,
`the parame—ters of the long term analysis filter,
`the LTP
`lag and the LTP gain, are estimated and updated in the LTP
`analysis block, on the basis of the current sub-block of the
`present and a stored sequence of the 120 previous reconstructed
`short term residual samples.
`
`A block of 40 long term residual signal samples is obtained by
`subtracting 40 estimates of the short term residual signal from
`the short term residual signal itself. The resulting block of 40
`long term residual samples is fed to the Regular Pulse Excitation
`analysis which performs the basic compression function of the
`algorithm.
`
`RPXExmbH1012-Page9
`RPX Exhibit 1012 - Page 9
`
`
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 9
`
`Version 3.2.0
`x...-
`
`the block of 40 input long term
`As a result of the RPE—analysis,
`residual samples are represented by one of 4 candidate
`sub—sequences of 13 pulses each. The subsequence selected is
`identified by the RPE grid position (M). The 13 RPE pulses are
`encoded using Adaptive Pulse Code Modulation (APCM) with
`estimation of the sub-block amplitude which is transmitted to the
`decoder as side information.
`
`‘The RPE parameters are also fed to a local RPE decoding and recon-
`struction module which produces a block of 40 samples of the quan-
`tized version of the long term residual signal.
`
`By adding these 40 quantized samples of the long term residual to
`the previous block of short term residual signal estimates, a
`reconstructed version of the current short term residual signal is
`obtained.
`
`‘The block of reconstructed short term residual signal samples is
`then fed to the long term analysis filter which produces the new
`block of 40 short term residual signal estimates to be used for
`the next sub-block thereby completing the feedback loop.
`
`1.6. PRINCIPLES OF THE RPE-LTP DECODER
`
`The simplified block diagram of the RPE—LTP decoder is shown in
`fig 1.2. The decoder includes the same structure as the feed—back
`loop of the encoder. In error—free transmission,
`the output of
`this stage will be the reconstructed short term residual samples.
`These samples are then applied to the short term synthesis filter
`followed by the de—emphasis filter resulting in the reconstructed
`speech signal samples.
`
`1.7. SEQUENCE AND SUBJECTIVE IMPORTANCE OF ENCODED PARAMETERS
`
`K
`
`As indicated in fig 1.1 the three different groups of data are
`produced by the encoder are:
`
`— the short term filter parameters,
`— the Long Term Prediction (LTP) parameters
`— the RPE parameters
`
`The encoder will produce this information in a unique sequence and
`format, and the decoder must receive the same information in the
`same way.
`In table 1.1,
`the sequence of output bits bl
`to b26O and
`the bit allocation for each parameter is shown.
`
`RPXEXMbH1012-Page10
`RPX Exhibit 1012 - Page 10
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 10
`
`Version 3.2.0
`Au .
`
`The different parameters of the encoded speech and their
`individual bits have unequal
`importance with respect to subjective
`quality. Before being submitted to the channel encoder,
`the bits
`have to be rearranged in the sequence importance as given in table
`1.2. The ranking has been determined by subjective testing and the
`procedure used is described in annex 2.
`
`Parameter Parameter
`number
`
`Parameter
`name
`
`Var. Number
`name of bits
`
`Bit no.
`(LSB-MSB)
`
`FILTER
`
`PARAMETERS
`
`LTP
`PARAMETERS
`
`RPE
`PARAMETERS
`
`1
`2
`3
`4
`5
`6
`7
`8
`
`9
`10
`
`11
`12
`13
`14
`
`55
`
`Log. Area
`ratios
`l - 8
`
`LTP lag
`LTP gain
`
`LAR 1
`LAR 2
`LAR 3
`LAR 4
`LAR 5
`LAR 6
`LAR 7
`LAR 8
`
`N1
`bl
`
`RPE grid position
`Block amplitude
`RPE-pulse no.1
`RPE—pulse no.2
`
`M1
`Xmaxl
`xl(0)
`xl(l)
`
`PPP-pulse no.1é
`
`xl(12)
`
`6
`6
`5
`5
`4
`4
`3
`3
`
`7
`2
`
`2
`6
`3
`3
`
`3
`
`- b6
`bl
`— bl2
`b7
`bl3 - b17
`bl8 — b22
`b23 - b26
`b2? — b30
`b31 - b33
`b34 - b36
`
`1:37 '- 1243
`b44 - b45
`
`b46 - b4?
`b48 — bS3
`b54 - b56
`b5? - b59
`
`b9O 1 b92
`
`==============___________=______._....._____..-.___._:======._____=_======_
`
`LTP
`PARAMETERS
`
`RPE
`PARAMETERS
`
`26
`27
`
`28
`29
`30
`31
`
`LTP lag
`LTP gain
`
`N2
`‘b2
`
`RPE grid position
`Block amplitude
`RPE—pulse no.1
`RPE—pulse no.2
`
`M2
`Xmax2
`x2(0)
`x2(l)
`
`7
`2
`
`2
`6
`3
`3
`
`b93 - b99
`b100- 10101
`
`b102— bl03
`.bl04— bl09
`bllO— b112
`bl13— bllS
`
`b14é1'b14s
`3
`x2(12)
`P\PP-pulse no.l3
`xii
`._.._._=_.._......._-.__._.__..__-.._..__.........._..._____.__..-___=.._..._.-..._==:_......=--=_=:
`
`Table 1.1a. Encoder output parameters in order of occurrence and
`bit allocation within the speech frame of 260 bits/20
`ms
`
`RPX Exhibit 1012 - Page 11
`RPX Exhibit 1012 - Page 11
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 11
`
`Version 3.2.0
`
`Sub—frame no.3
`
`LTP
`PARAMETERS
`
`RPE
`PARAMETERS
`
`43
`44
`
`45
`46
`47
`48
`
`éé
`
`LTP lag
`LTP gain
`
`N3
`b3
`
`RPE grid position
`Block amplitude
`RPE—pulse no.1
`RPE-pulse no.2
`
`M3
`Xmax3
`X3(0)
`x3(l)
`
`ééé—pu1se no.l3
`
`x3(l2)
`
`7
`2
`
`2
`6
`3
`3
`
`3
`
`bl49— b1S5
`bl56- bl57
`
`bl58— b159
`bl60— b165
`bl66- bl68
`bl69— bl7l
`
`bzoéi b204
`
`==_._.====_..._.._.____..._....-_____.___..........._-.......‘..._....—._.____-....._‘._......._....._........_..
`
`LTP
`PARAMETERS
`
`RPE
`PARAMETERS
`
`60
`61
`
`62
`63
`64
`65
`
`fié
`
`LTP lag
`LTP gain
`
`N4
`b4
`
`RPE grid position
`Block amplitude
`RPE—pulse no.1
`RPE—pulse no.2
`
`M4
`Xmax4
`x4(O)
`x4(1)
`
`ééé—pu1se no.13
`
`x4(12)
`
`7
`2
`
`2
`6
`3
`3
`
`3
`
`b205— b2ll
`b2l2— b2l3
`
`b214— b2l5
`b2l6— b221
`b222- b224
`b22S- b227
`
`b25él'b26o
`
`Table l.lb. Encoder output parameters in order of occurrence and
`bit allocation within the speech frame of 260 bits/20
`ms
`
`RPX Exhibit 1012 - Page 12
`RPX Exhibit 1012 - Page 12
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 12
`
`Version'3.2.0
`
`
`
`
`
`.___..-.__..__.__.___...._-...._.___.___..__.._._.......________________====.:=_====..====
`
`Order of bit
`importance
`
`Parameter
`
`number
`
`1
`1
`12,29,46,63
`
`|bUJ!\.)|—-‘U-lt\)I—‘
`
`vhbJl\.)|—‘Lr)t\Jl—‘
`
`9,26,43,60
`l2,29,46,63
`2,5,6
`9,26,43,60
`9,26,43,60
`9,26,43,60
`9,26,43,60
`l2,29,46,63
`
`147
`
`Log.area ratio 1
`b53,b109,bl65,b22l
`Block amplitude
`b5
`Log.area ratio
`bl2
`Log.area ratio
`bl7
`Log.area ratio
`b4
`Log.area ratio
`bll
`Log.area ratio
`bl6
`Log.area ratio
`b22
`Log.area ratio
`b43,b99,b155,b2ll
`LTP lag
`b52,blO8,bl64,b220
`Block amplitude
`blO.b26,b30
`Log.area ratio 2,5,6
`b42,b98,bl54,b2l0
`LTP lag
`b4l,b97,bl53,b209
`LTP lag
`b40,b96,blS2,b208~
`LTP lag
`b39,b95,b1Sl,b207
`LTP lag
`b51,bl07,bl63,b2l9
`Block amplitude
`b3
`Log.area ratio 1
`b21
`Log.area ratio 4
`b33
`Log.area ratio 7
`b38,b94,b150,b206
`9,26,43,60
`LTP lagl
`==_._===:=..==..==._=_.__._-.....-_..._.._-.._...._.._._...__.______=_==__..__.__=-=======
`
`
`
`
`
`
`
`
`
`
`
`
`7
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`S 6
`Log.area ratio 5,6
`1o,2$,44,61
`LTP gain
`9,26,43,60
`LTP lag
`ll,28,45,62
`Grid position
`1
`Log.area ratio 1
`Log.area ratio 2,3,8,4 2,3,8,4
`5,7
`Log.area ratio 5,7
`10,27,44,61
`LTP gain
`l2,29,46,63
`Block amplitude
`l3..25
`RPE pulses
`30..42
`RPE pulses
`47..59
`RPE pulses
`64..76
`RPE pulses
`ll,28,45,62
`Grid position
`l2,29,46,63
`Block amplitude
`l3..25
`RPE pulses
`30..42
`RPE pulses
`47..S9
`RPE pulses
`64..67
`RPE pulses
`
`b25,b29
`b4S,bl0l,bl57,b2l3
`b37,b93,bl49,b205
`b47,bl03,blS9,b2l5
`b2
`b9,b15,b36,b20
`b24.b32
`b44,blOO,bl56,b212
`b50,bl06,bl62.b2l8
`b56,bS9,..,b92
`bll2,bll5,...bl48
`bl68,bl7l,..,b204
`b224,b227,..,b260
`b46,b102,b158,b2l4
`b49,b105,bl61,b2l7
`b55,b58,..,b9l
`bl11,bll4,..,bl47.
`bl67,bl70,..,b203
`b223,b226,b229,b232
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Table 1.2a. Subjective importance of encoded bits (the parameter
`and bit numbers refer to table l.1)
`
`RPX Exhibit 1012 - Page 13
`RPX Exhibit 1012 - Page 13
`
`
`
`IETSI/GSM
`
`GSM 06.10 / page 13
`
`Version 3.2.0
`
`Class II
`
`183...
`
`259,260
`
`RPE pulses
`Log.area ratio 1
`Log.area ratio 2,3,6
`Log.area ratio 7
`Log.area ratio 8
`Log.area ratio 8,3
`Log.area ratio 4
`Log.area ratio 4,5
`Block amplitude
`RPE pulses
`RPE pulses
`RPE pulses
`RPE pulses
`Log.area ratio 2,6
`
`68..76
`1
`2,3,6
`7
`8
`8,3
`4
`4,5
`12,29,46,63
`13..25
`30..42
`47..S9
`64..76
`2,6
`
`b23S,b238,...b259
`bl
`b8,bl4,b28
`b31
`b35
`b34,bl3
`bl9
`bl8,b23
`b48,b104,b160,b2l6
`bS4,bS7,..,b90
`bl10,bll3,..,b146
`bl66,b169,..,b202
`b222,b225,..,b258
`b7,b27
`
`Table l.2b. Subjective importance of encoded bits (the parameter
`and bit numbers refer to table 1.1)
`
`NQIE: The subdivisions in table 1.2 indicate the border between
`protection classes Ia,
`Ib and II as defined in recommendation
`GSM 05.03.
`
`RPX Exhibit 1012 - Page 14
`RPX Exhibit 1012 - Page 14
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 14
`
`Version 3.2.0
`
`Reflection
`coefficiens coded as
`Log. - Area Ratios
`(36 bits/20 ms)
`
`
`
`
`
`RPE parameters
`(47 bits/5 ms)
`
`
`
`
`RPE grid
`decoding and
`
`positioning
`
`
`
`
`processing
`
`|nP'-It
`
`signal
`
`
`
`LTP parameters
`(9 bits/5 ms)
`
`‘
`
`:
`}
`
`In II
`
`
`
`
`{
`T°
`{
`radio
`subsystem }
`
`i5
`
`(1) Short term residual
`(2) Long term residual (40 samples)
`(3) Short term residual estimate (40 samples)
`(4) Reconstructed short term residual (40 samples)
`(5) Quantized long term residual (40 samples)
`
`Fi 1.1. Sim lified block dia ram of the RPE — LTP encoder
`
`RPX Exhibit 1012 - Page 15
`RPX Exhibit 1012 - Page 15
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 15
`
`Version 3.2.0
`An
`
`I
`
`Réflection coefficients coded
`a§ Log.—Area Ratios
`(3'E bits/20 ms)
`
`1I
`
`
`
`
`I1II 1PI
`
`R E
`
`
`
`RPE gn'd
`decoding and
`positioning
`
`processing
`
`Output
`
`
`
`signg
`
`
`
`
`parameters
`(4? bits/5 ms)
`I
`
`Fig 1.2. Simglified block diagram of the RPE — LTP decoder
`
`RPX Exhibit 1012 - Page 16
`RPX Exhibit 1012 - Page 16
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 16.
`
`Version 3.2.0
`
`2. TRANSMISSION CHARACTERISTICS
`
`M’
`
`This section specifies the necessary performance characteristics
`of the audio parts for proper functioning of the speech trancoder.
`some transmission performance characteristics of the RPE-LTP
`transcoder are also given to assist the designer of the speech
`transcoder function. The information given here is redundant and
`the detailed specifications are contained in recomendation GSM
`L 11.10.
`
`The performance characteristics are referred to the 13 bit uniform
`PCM interface.
`
`the
`NQEE: To simplify the verification of the specifications,
`performance limits may be referred to an A~law measurement
`interface according to CCITT Rec-omendation G.711.
`In this
`way, standard measuring equipments for PCM systems can be
`‘
`utilized for measurements.
`The relationship between the 13
`bit format and the A—law companded shall follow the
`procedures defined in section 1.4.
`
`2.1. PERFORMANCE CHARACTERISTICS OF THE ANALOGUE/DIGITAL
`INTERFACES
`
`Concerning 1) discrimination against out—of—band signals (sending)
`and 2) spurious out—of—band signals (receiving).
`the same
`requirements as defined in ETSI standard TE 04-15 (digital
`telephone, candidate NET33) apply.
`
`2.2. TRANSCODER DELAY
`
`Consider a back to back configuration where the parameters
`generated by the encoder are delivered to the speech decoder as
`soon as they are available.
`
`The transcoder delay is defined as the time interval between the
`instant a speech frame of 160 samples has been received at the
`encoder input and the instant the corresponding 160 reconstructed
`speech samples have been out-put by the speech decoder at an 8 kHz
`sample rate.
`
`The theoretical minimum delay which can be achieved is 20 ms.
`requirement is that the transcoder delay should be less than 30
`ms.
`
`The
`
`RPXExNbH1012-Page17
`RPX Exhibit 1012 - Page 17
`
`
`
`, ETSI/GSM
`
`GSM 06.10 / page 17
`
`Version 3.2.0
`
`3. FUNCTIONAL DESCRIPTION OF THE RPE-LTP CODEC
`.___.__.._.__=_...__...__._..._..._._._.....___.___...._..._._.__._...._==..
`
`«W»
`
`The block diagram of the RPE—LTP-coder is shown in fig 3.1. The
`individual blocks are described in the following sections.
`
`3.1. FUNCTIONAL DESCRIPTION OF THE RPE-LTP ENCODER
`
`The Brep;ggessing_segtiQg of the RPE—LTP encoder comprises the
`following two sub—blocks:
`
`* Offset compensation (3.1.l)
`* Preemphasis (3.1.2)
`
`The L2g_analxsi§_segti9n of the RPE—LTP encoder comprises the
`following five sub—blocks:
`
`* segmentation (3.l.3)
`* Auto—Correlation (3.1.4)
`* Schur Recursion (3.1.5)
`* Transformation of reflection coefficients to Log.—Area Ratios
`(3.1.6)
`* Quantization and coding of Log.—Area Ratios (3.1.7)
`
`The
`the following four sub—blocks:
`
`of the RPE-LTP comprises
`
`* Decoding of the quantized Log.—Area Ratios (LARs)
`* Interpolation of Log.—Area Ratios (3.1.9)
`* Transformation of Log.—Area Ratios into reflection coefficients
`(3.1.10)
`* Short
`term analysis filtering (3.1.l1)
`
`(3.l.8)
`
`The comprises 4 sub-blocks
`working on subsegments (3.l.l2) of the short term residual
`samples.
`
`It->1-#35
`
`.
`Calculation of LTP parameters (3.l.l3)
`Coding of the LTP lags (3.l.l4) and the LTP gains (3.l.l5)
`Decoding of the LTP lags (3.1.14) and the LTP gains (3.l.l5)
`Long term analysis filtering (3.l.l6), and
`Long term synthesis filtering (3.l.17)
`
`RPXEXMbH1012-Page18
`RPX Exhibit 1012 - Page 18
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 18
`
`Version 3.2.0
`
`The EPE encoding section comprises five different subfblocks:
`
`* *
`
`Weighting filter (3.l.l8)
`Adaptive sample rate decimation by RPE grid selection (3.1.19)
`* APCM quantization of the selected RPE sequence (3.l.20)
`* APCM inverse quantization (3.l.21)
`* RPE grid positioning (3.1.22)
`
`' Pnzpgggnssggg ssggggg
`
`3.1.1. Offset compensation
`
`Prior to the speech encoder an offset compensation,by a notch
`filter is applied in order to remove the offset of the input
`signal so to produce the offset—free signal sof.
`
`Sof(k) = so(k)
`
`- sO(k—1) + alpha*sOf(k—l)
`
`(3.1.1)
`
`alpha = 32735*2‘15
`
`3.1.2. Preemphasis
`
`The signal sof is applied to a first order FIR preemphasis
`filter leading to the input signal s of the analysis section.
`
`s(k)
`
`= sOf(k)
`
`— beta*sOf(k—l)
`
`(3.l.2)
`
`beta: 2a1eo*2'15
`
`P
`
`ALY I
`
`I
`
`3.1.3. Segmentation
`
`is divided into non—overlapping frames
`The speech signal s(k)
`having a length of To = 20 ms
`(160 samples). A new LPC~analysis
`of order p=8 is performed for each frame.
`
`RPX Exhibit 1012 - Page 19
`RPX Exhibit 1012 - Page 19
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 19
`
`V
`
`Version 3.2.0
`
`3.1.4. Autocorrelation
`
`The first p+l = 9 values of the Auto—Correlation function are
`calculated by
`
`AC1-"(k)=
`
`LS2
`>__ s(i)s(i-k)
`i=k
`
`,k
`
`0.l...,8
`
`(3.2)
`
`3.1.5. Schur Recursion
`
`The reflection coefficients are calculated as shown in Fig 3.2
`using the Schur Recursion algorithm. The term “reflection
`Vcoefficient" comes from the theory of linear prediction of speech
`(LPC), where a vocal tract representation consisting of series of
`uniform cylindrical sections is assumed. Such a representation can
`be described by the reflection coefficents or the area ratios of
`connected sections.
`
`3.1.6. Transformation of reflection coefficients to Log.—Area
`Ratios
`
`The reflection coefficients r(i),
`Schur algorithm, are in the range
`
`(i=1..8), calculated by the
`
`-1 <= r(i) <= + 1
`
`the reflection
`Due to the favourable quantization characteristics,
`coefficients are converted into Log.—Area Ratios which are
`~
`strictly defined as follows:
`
`Logarea(i) = loglo
`
`( —————— -j-—)
`
`(3.3)
`
`Since it is the companding characteristic of this transformation
`that is of importance,
`the following segmented approximation is
`used.
`
`RPX Exhibit 1012 - Page 20
`RPX Exhibit 1012 - Page 20
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 20
`
`Version 3.2.0
`
`LAR(i)
`
`|r(i) |J_:< 0.675
`;
`r(i)
`= sign[r(i)]*[2|r(i)I-0.675] ; 0.675 <= 1r(i)I < 0.950
`sign[r(i)]*[8lr(i)I-6.375] ; 0.950 <= lr(i)l <= 1.000
`
`(3.4)
`
`with the result that instead of having to divide and obtain the
`logarithm of particular values, it is merely necessary to
`. multiply, add and compare these values.
`
`The following equation (3.5) gives the inverse transformation.
`
`LAR'(i)
`r'(i)=sign[LAR'(i)]*[0.500*lLAR'(i)I
`+0.3375001
`sign[LAR'(i)]*[O.l25*lLAR'(i)l
`+0.796875]
`
`;
`
`lLAR'(i)I<O.675
`'
`; 0.675<=lLAR'(i)|<l.225
`
`;
`
`l.225<=|LAR'(i)|<=l.625
`
`(3.5)
`
`3.1.7. Quantization and coding of Log.-Area Ratios
`
`The Log.—Area Ratios LAR(i) have different dynamic ranges and
`different asymmetric distribution densities. For this reason,
`transformed coefficients LAR(i) are limited and quantized
`differently according to the following equation (3.6), with LARc(i)
`denoting the quantized and‘integer coded version of LAR(i).
`
`the
`
`LARC(i)
`
`= Nint{A(i)*LAR(i) + B(i))
`
`(3.6)
`
`with
`
`Nintfz} := int(z+sign{z}*0.5}
`
`(3.6a)
`
`”
`
`Function Nint defines the rounding to the nearest integer value,
`with the coefficients A(i), B(i), and different extreme values of
`LARc(i)
`for each coefficient LAR(i) given in table 3.1-
`
`RPX Exhibit 1012 - Page 21
`RPX Exhibit 1012 - Page 21
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 21
`
`Version 3.2.0
`
`I Minimum I Maximum I
`| B(1)
`I A(i)
`ILAR No 1
`I LARC(i)
`I LARc(i)
`I
`I
`I
`I
`I ------- --I ------ --I ------ —-I ------- --I ------- --I
`I
`1
`I 20.000 I
`0.000 I
`-32
`I
`+31
`I
`I
`2
`I 20.000 I
`0.000 I
`-32
`I
`+31
`1
`I
`3
`I 20.000 I
`4.000 I
`-16
`I
`+15
`I
`I
`4
`I 20.000 I
`-5.000 I
`-16
`I
`+15
`I
`I
`5
`I 13.637 I
`0.184 I
`- 8
`I
`+ 7
`I
`I
`6
`I 15.000 I
`-3.500 I
`- 8
`I
`+ 7
`I
`I
`7
`I
`8.334 I
`-0.666 I
`- 4
`I
`+ 3
`I
`I
`8
`I
`8.824 I
`-2.235 I
`— 4
`I
`+ 3
`I
`
`T-
`
`AL
`
`F
`
`EI
`
`The current frame of the speech signal s is retained in memory
`until calculation of the LPC parameters LAR(i)
`is completed. The
`frame is then read out and fed to the short term analysis filter
`of order p=8. However, prior to the analysis filtering operation,
`the filter coefficients are decoded and preprocessed by
`interpolation.
`
`3.1.8. Decoding of the quantized Log.—Area Ratios
`
`In this block the quantized and coded Log.—Area Ratios (LARC(i)) are
`decoded according to equation (3.7).
`
`LAR"(i)
`
`I LAR¢(i)
`
`- B(i) )/ A(i)
`
`(3.7)
`
`3.1.9. Interpolation of Log.—Area Ratios
`
`To avoid spurious transients which may occur if the filter
`coefficients are changed abruptly,
`two subsequent sets of
`Log.—Area Ratios are interpolated linearly. Within each frame of
`160 analysed speech samples the short term analysis filter and the
`short term synthesis filter operate with four different sets of
`coefficients derived according to table 3.2.
`
`RPX Exhibit 1012 - Page 22
`RPX Exhibit 1012 - Page 22
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 22
`
`Version 3.2.0
`
`II
`
`I O.75*LAR"J_l(i) + O.25*LAR"J(i)
`..
`I
`I 13...26 I 0.5O*LAR"J_l(i)
`+ 0.50*LAR"J(i)
`I 27...39 I 0.25*LAR"J_1(i) + O.75*LAR"J(i)
`I
`I
`LAR"JIi)
`
`I
`I
`I
`I
`
`3.1.10. Transformation of Log.—Area Ratios into reflection
`coefficients
`
`?he reflection coefficients are finally determined using the
`inverse transformation according to equation (3.5).
`
`3.1.11. Short Term Analysis Filtering
`
`term analysis filter is implemented according to the
`The Short
`lattice structure depicted in fig 3.3.
`
`d0(k) = s(k)
`u0(k)
`= s(k)
`+ r'i*u-_1(k—l) with i=1,...8
`di(k) = di_1(k)
`ui(k)
`= ui_ (k—1) + r'i*di_1(k)
`with i=1,...8
`d(k )
`= d8(i)
`
`‘
`
`(3.8a)
`(3.8b)
`(3.8c)
`(3.8d)
`(3.8e)
`
`L
`
`- ERM RED
`
`'1'
`
`3.1.12. Sub—segmentation
`
`Each input frame of the short term residual signal contains 160
`samples, corresponding to 20 ms. The long term correlation is
`evaluated four times per frame, for each 5 ms subsegment. For
`convenience in the following, we note j=0,...,3 the sub-segment
`number, so that the samples pertaining to the j—th sub—segment of
`the residual signal are now denoted by d(kj+k) with j
`0,...,3; kj =
`k0 + j*40 and k = O,...,39 where k0 corresponds to the first value of
`the current frame.
`
`RPX Exhibit 1012 - Page 23
`RPX Exhibit 1012 - Page 23
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 23
`
`Version 3.2.0
`
`3.1.13. Calculation of the LTP parameters
`
`For each of the four sub-segments a long term correlation lag Nj,
`(j=O,...,3), and an associated gain factor b-,
`(j=O,...,3)
`are determined. For each sub-segment,
`the determination of these
`parameters is implemented in three steps.
`
`1) The first step is the evaluation of the cross-correlation
`Rj(lambda) of the current sub-segment of short term residual
`signal d(k-+i),(i=‘,...,39) and the previous samples of the
`reconstructed shoi- term residual signal d‘(kj+i),
`(i=—l20,...,-1):
`
`Rj(lambda)
`
`=
`
`..3
`= 0,
`j
`fig
`;_ d(kj+i)*d'(kj+i—lambda); kj = k0 + j*40
`i=0
`lambda = 40,
`
`,12O
`
`The cross—correlation is evaluated for lags lambda greater than
`or equal to 40 and less than or equal to 120,
`ie corresponding
`to samples outside the current sub—segment and not delayed by
`more than two sub—segments.
`‘
`
`(3.9)
`
`2) The second step is to find the position Nj of the peak of
`the cross—correlation function within this interval:
`
`Rj(Nj) = max { Rj(lambda);
`
`lambda = 40..l20 };
`
`j = O,...,3
`
`~
`
`(3.10)
`
`3) The third step is the evaluation of the gain factor bj
`according to:
`
`bj =
`with
`
`/
`
`j: OI"'I3
`
`Sj(Nj) =
`
`2
`
`3'3‘
`i:Od'
`
`.
`(kj+1-Nj)7
`
`.
`3
`
`= 0,,..,3
`
`(3.12)
`
`RPX Exhibit 1012 - Page 24
`RPX Exhibit 1012 - Page 24
`
`
`
`ETSI/GSM
`
`GSM 06.10 / page 24
`
`Version 3.2.0
`
`It is clear that the last 120 samples of the reconstructed
`short term residual signal d'(kj+i),(i=—l20,...,—l) must be
`retained until the next sub—segment so as to allow the
`evaluation of the relations (3.9),...,(3.l2).
`
`3.1.14. Coding/Decoding of the LTP lags
`
`The long term correlation lags N-,(j=0,...,3) can have values
`in the range (40,...,120), and so must be code