FED-STD 1016
expressed in terms of frequency (Hz) and must be monotonic (i.e., higher numbered LSPS must not
contain lower frequencies than lower numbered LSPS).
LSP1O
LSP8
LSP9
LSP7
LSP5
LSP6
Index
LSP
LSP2
LSP3
LSP4
.
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
(Hz)
2,760
1,800
2,225
3,190
210
420
620
1,000
1,470
0
2,880
2,400
1,880
3,270
460
235
660
1,050
1,570
1
170
2,525
1,960
3,350
3,000
1,130
1,690
2
225
265
500
720
2,650
2,100
3,100
3,420
295
795
1,830
3
540
250
2,800
2,300
3,200
3,490
880
1,285
4
2,000
325
585
280
2,950
3,310
2,480
3,590
1,350
970
2,200
360
5
340
640
2,700
3,430
3,710
6
420
400
705
1,080
2,400
3,150
2,900
7
3,550
3,830
440
775
1,170
1,510
2,600
3,350
500
480
1,270
850
9
520
1,670
950
10
1,750
1,050
1,470
560
1,850
11
1,570
1,150
610
1,950
12
1,670
670
1,250
740
13
1,350
2,050
14
1,870
810
2,150
15
1,970
1,550
880
2,250
.
3.7.3 LSP Weighted Averaging. To determine the LSP values to be used for each subframe,
weighted averaging is used between the LSPS transmitted with the previous frame and the LSPS
transmitted with the present frame. For each of the
of a given frame, the following
weighting is given to the LSPS transmitted with the previous and present frames before they are
utilized.
Present
Previous LSPS
7/8
1/8
1
2
3/8
5/8
5/8
3
3/8
7/8
4
1/8
Thus, for example, if LSP 1 of a frame is 250 Hz and LSP 1 of the previous frame was 340 Hz, the
value used for
of the present frame is: 7/8(340 Hz) + 1 /8(250 Hz) = 328.75 Hz. For each
this method of weighted averaging is employed for all 10 LSPS.
3.8 Transmission Format
3.8.1 Transmission Rate. The transmission rate for CELP shall be 4,800 bits/s
percent.
3.8.2 Bit Assignment. The table below gives the assignment of the 144 bits in each CELP frame
(30 ms at 4,800 bits/s). Order of transmission is from bit 1 to bit 144. Abbreviations used in the
following table are:
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