IEEE 802.16 OFDMA Introduction
New Technologies about IEEE 802.16:
IEEE 802.16's Task Group e is developing, under IEEE PAR 802.16e, an amendment to IEEE Standard 802.16 ("Air Interface for Fixed Broadband Wireless Access Systems") as modified by IEEE Standards 802.16a and 802.16c. The 802.16e amendment covers "Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands".
IEEE 802.16f (approved by IEEE-SA Standards Board, 04/08/12):
Draft Amendment to IEEE Standard for Local and Metropolitan Area Networks - Part 16: Air Interface for Fixed Broadband Wireless Access Systems - Management Information Base
IEEE 802.16g (approved by IEEE-SA Standards Board, 04/08/12):
Draft Amendment to IEEE Standard for Local and Metropolitan Area Networks - Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems - Management Plane Procedures and Services
IEEE 802.16h (was approved by the IEEE-SA Standards Board on 2004/12/08):
License-Exempt (LE) Task Group is developing a draft under the P802.16h PAR.
IEEE 802.16.2: under IEEE PAR 802.16.2-REVa, a revision of IEEE Standard 802.16.2 ("IEEE Recommended Practice for Local and metropolitan area networks - Coexistence of Fixed Broadband Wireless Access Systems"). The draft was approved as IEEE Standard 802.16.2-2004 by the IEEE-SA Standards Board on 9 February 2004. It was published on 17 March 2004.
Comments for FCC Spectrum Policy Task Force on Spectrum Policy
1. Data subcarriers for data transmission.
2. Pilot subcarriers for various estimation and synchronization purposes.
3. Null subcarriers for no transmission at all, used for guard bands and DC carriers.
Active subcarriers are divided into subsets of subcarriers called subchannels. The subcarriers forming one subchannel may be, but need not be, adjacent. Bandwidth and MAP allocations are done in subchannels.
AMC subchannels, Hybrid Automatic Repeat Request (H-ARQ), high-efficiency Uplink (UL) subchannel structures, Multiple-Input-Multiple-Output (MIMO) diversity, enhanced Advanced Antenna Systems (AAS), and coverage enhancing safety channels.
Table: OFDM Scalability Parameters:
|System bandwidth (MHz)||1.25||2.5||5||10||20|
|Sampling frequency (Fs,MHz)||1.429||2.857||5.714||11.429||22.857|
|Sample time (1/Fs,nsec)||700||350||175||88||44|
|FFT size (NFFT)||128||256||512||1024||2048|
|Subcarrier frequency spacing||11.16071429 kHz|
|Useful symbol time (Tb=1/ f)||89.6 μs|
|Guard time (Tg=Tb/8)||11.2 μs|
|OFDMA symbol time (Ts=Tb+Tg)||100.8 μs|
A new standard IEEE 802.22 is being defined as regional area networks. Such networks operate in the VHF/UHF bands, and include mechanisms to protect incumbent radio systems (terrestrial TV broadcast) from harmful interference, by means of incumbent identification.