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AIR INTERFACE FOR FIXED BROADBAND WIRELESS ACCESS SYSTEMS

IEEE Std 802.16-2001

(ITU-R P.452 [B12]). The effect of rain decorrelation may be estimated based on cell sector size and the specified frequency re-use plan.

A significant mitigation technique for the control of both intrasystem and intersystem interference is the angular discrimination provided by system antennas. The antenna radiation pattern envelope (RPE) discrimination has significance for both clear sky and rain faded propagation conditions. The RPE requirements for aggressive intrasystem frequency reuse plans may exceed the RPE requirements for the control of inter-system coexistence. Recommended antenna RPE characteristics are described in IEEE Std 802.16.2-2001.

8.2.9.2 Transmitter characteristics

Unless stated otherwise, the transmitter requirements are referenced to the transmitter output port and apply with the transmitter tuned to any channel.

8.2.9.2.1 Output power

In the following subclause, power is defined as the time-averaged power when emitting a signal (excluding off-time between bursts), measured over the scrambled bits of one transmitted burst.

The power at which SS or BSs shall operate is specified in the following subclause.

8.2.9.2.1.1 BS

A BS shall not produce an effective isotropic radiated power (EIRP) spectral density exceeding either +14 dBW/MHz or local regulatory requirements. The recommendations in 6.1.1.1 of IEEE Std 802.16.2-2001 should be followed.

8.2.9.2.1.2 SS

An SS shall not produce an EIRP spectral density exceeding either +30 dBW/MHz or local regulatory requirements. The recommendations in 6.1.1.2 of IEEE Std 802.16.2-2001 should be followed.

8.2.9.2.2 Emission mask

Local regulation requirements typically dictate emission mask requirements. For example, in its territories, ETSI currently specifies the use of Type A (QPSK), Type B (16-QAM) and Type C (64-QAM) masks (ETSI EN 301 213-3). These masks are presented in Figure 126, Figure 127, and Figure 128.

In the case of mixed modulation systems (e.g., adaptive modulation), ETSI currently specifies the most stringent mask associated with the highest modulation complexity in the adjacent channels.

NOTE—This requirement is under review by ETSI.

In cases where alternative masks are permitted, the emission mask specified shall be the ETSI Type B mask [ETSI EN 301 213-3] (Figure 127).

Copyright © 2002 IEEE. All rights reserved.

261

IEEE Std 802.16-2001

LOCAL AND METROPOLITAN AREA NETWORKS—PART 16:

Spectral Density [dB]

0

–23

–45

A

B

C

D

Frequency Offset from

E Channel Center [MHz]

Point

A

B

C

D

E

Value in

11c/28

19c/28

25c/28

45c/28

5c/2

MHz

 

 

 

 

 

Note: c is the channel size in MHz

Figure 126—ETSI Type A spectrum mask

Spectral Density [dB]

0

–32

–37

–50

A

B

C

D

E

Frequency Offset from

Channel Center [MHz]

 

 

 

 

 

Point

A

B

C

D

E

Value in

11.2C/28

22.4C/28

C

2C

5C/2

MHz

 

 

 

 

 

Note: C is defined as channel size in MHz (i.e., 28 MHz)

Figure 127—ETSI Type B spectrum mask

262

Copyright © 2002 IEEE. All rights reserved.

AIR INTERFACE FOR FIXED BROADBAND WIRELESS ACCESS SYSTEMS

IEEE Std 802.16-2001

0

 

 

 

 

 

 

 

 

 

 

 

 

 

Density [dB]

–13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Spectral

 

–34

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

–42

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

–52

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Frequency Offset from

 

 

A

B

 

C

 

D

 

E Channel Center [MHz]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Point

 

A

 

B

 

C

D

 

 

 

E

 

 

Value in

 

C/2

 

22.4C/28

 

C

2C

 

 

 

5C/2

 

 

MHz

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: C is defined as channel size in MHz (i.e., 28 MHz)

Figure 128—ETSI Type C spectrum mask

8.2.9.2.3 Modulation accuracy and error vector magnitude (EVM)

The EVM defines the average constellation error with respect to the farmost constellation point power, as illustrated in Figure 129 and defined by the following equation:

 

N

 

 

 

 

1

2

2

)

 

---(∆I

 

+ Q

EVM =

N 1

 

 

 

----------------------------------------

 

 

 

Smax2

where N is the number of symbols in the measurement period and Smax the maximum constellation amplitude.

The EVM shall be measured over the continuous portion of a burst occupying at least 1/4 of the total transmission frame at maximum power settings.

Copyright © 2002 IEEE. All rights reserved.

263

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