Orthogonal frequency-division multiplexing
OFDM system comparison table
Key features of some common OFDM-based systems are presented in the following table.

Orthogonal frequency-division multiplexing

Section Title: OFDM system comparison table
Table Section Text: Key features of some common OFDM-based systems are presented in the following table.

Standard name	DAB Eureka 147	DVB-T	DVB-H	DMB-T/H	DVB-T2	IEEE 802.11a

Ratified year	1995	1997	2004	2006	2007	1999

Frequency range of today's equipment	174–240 MHz 1,452–1,492 GHz	470–862 MHz 174–230 MHz	470–862 MHz	470–862 MHz	4,915–6,100 MHz

Channel spacing, B [MHz]	1.712	6, 7, 8	5, 6, 7, 8	8	1.7, 5, 6, 7, 8, 10	20

FFT size (k=1,024)	Mode I: 2k Mode II: 512 Mode III: 256 Mode IV: 1k	2k, 8k	2k, 4k, 8k	1 (single-carrier) 4k (multi-carrier)	1k, 2k, 4k, 8k, 16k, 32k	64

Number of non-silent sub-carriers, N	Mode I: 1,536 Mode II: 384 Mode III: 192 Mode IV: 768	2K mode: 1,705 8K mode: 6,817	1,705, 3,409, 6,817	1 (single-carrier) 3,780 (multi-carrier)	853-27,841 (1K normal to 32K extended carrier mode)	52

Sub-carrier modulation scheme	​π⁄4-DQPSK	QPSK, 16QAM or 64QAM	QPSK, 16QAM or 64QAM	4QAM, 4QAM-NR, 16QAM, 32QAM and 64QAM.	QPSK, 16QAM, 64QAM, 256QAM	BPSK, QPSK, 16QAM or 64QAM

Useful symbol length, TU (μs)	Mode I: 1,000 Mode II: 250 Mode III: 125 Mode IV: 500	2K mode: 224 8K mode: 896	224, 448, 896	500 (multi-carrier)	112-3,584 (1K to 32K mode on 8 MHz channel)	3.2

Additional guard interval, TG (fraction of TU)	24.6% (all modes)	​1⁄4, ​1⁄8, ​1⁄16, ​1⁄32	​1⁄4, ​1⁄8, ​1⁄16, ​1⁄32	​1⁄4, ​1⁄6, ​1⁄9	1/128, 1/32, 1/16, 19/256, 1/8, 19/128, 1/4. (For 32k mode maximum 1/8)	​1⁄4

Sub-carrier spacing (Hz)	Mode I: 1,000 Mode II: 4,000 Mode III: 8,000 Mode IV: 2,000	2K mode: 4,464 8K mode: 1,116	4,464, 2,232, 1,116	8 M (single-carrier) 2,000 (multi-carrier)	279-8,929 (32K down to 1K mode)	312.5 K

Net bit rate, R (Mbit/s)	0.576–1.152	4.98–31.67 (typically 24.13)	3.7–23.8	4.81–32.49	Typically 35.4	6–54

Link spectral efficiency R/B (bit/s/Hz)	0.34–0.67	0.62–4.0 (Typ 3.0)	0.62–4.0	0.60–4.1	0.87-6.65	0.30–2.7

Inner FEC	Conv coding with Equal error protection code rates ​1⁄4, ​3⁄8, ​4⁄9, ​1⁄2, ​4⁄7, ​2⁄3, ​3⁄4, ​4⁄5 Unequal error protection with av.	Conv. coding with code rates ​1⁄2, ​2⁄3, ​3⁄4, ​5⁄6, or ​7⁄8	Conv. coding with code rates ​1⁄2, ​2⁄3, ​3⁄4, ​5⁄6, or ​7⁄8	LDPC with code rates 0.4, 0.6 or 0.8	LDPC 1/2, 3/5, 2/3, 3/4, 4/5, 5/6	Conv. coding with code rates ​1⁄2, ​2⁄3, or ​3⁄4

Outer FEC (if any)	Optional RS (120, 110, t = 5)	RS (204, 188, t=8)	RS (204, 188, t=8) + MPE-FEC	BCH code (762, 752)	BCH code

Maximum travelling speed (km/h)	200–600	53–185 depends on transmission frequency

Time interleaving depth (ms)	384	0.6–3.5	0.6–3.5	200–500	up to 250 (500 with extension frame)

Adaptive transmission (if any)	None	None	None	None

Multiple access method (if any)	None	None	None	None

Typical source coding	192 kbit/s MPEG2 Audio layer 2	2–18 Mbit/s Standard - HDTV H.264 or MPEG2	H.264	Not defined (Video: MPEG-2, H.264 and/or AVS Audio: MP2 or AC-3)	H.264 or MPEG2 (Audio: AAC HE, Dolby Digital AC-3 (A52), MPEG-2 AL 2.)

Sentence(s)

IEEE 802.11a specifies per-stream data rates ranges from 6 to 54 Mbit/s.

final_sentence: IEEE 802.11a specifies per-stream data rates ranges from 6 to 54 Mbit/s.