发布时间 : 星期日 文章KDB 662911 多天线讲义-FCC认证更新完毕开始阅读8f1edeafa1116c175f0e7cd184254b35eefd1ab7
b) Sectorized antenna systems. In sectorized antenna systems in which each antenna is used
to transmit different data in a different direction from the other antennas, directional gain is equal to the gain of an individual sector antenna.
b）扇形天线系统。 在其中每个天线用于在与其它天线不同的方向上发射不同数据的扇区化天线系统中，定向增益等于单个扇区天线的增益。
c) Cross-polarized antennas. For a system in which the antennas have fixed orientations
relative to one another that ensure that the antennas are cross-polarized regardless of any user actions, the directional gain is computed as follows.
c）交叉极化天线。 对于其中天线具有相对于彼此的固定取向的系统，其确保天线是交叉极化的，而不管任何用户动作如何，方向增益计算如下。
(i)
Cross-polarized antennas with NANT = 2. In the case of a transmitter with only two outputs driving a pair of antennas that are cross-polarized (e.g., vertical and horizontal or left-circular and right-circular),
directional gain is the gain of an individual antenna. If the two antennas have different gains, the larger gain applies.
(ii) Multiple antennas, each of which has one of two (or three) polarizations
that are orthogonal to one another (i.e., cross polarized). (If three polarizations are used, all three polarizations must be mutually orthogonal.) The total gain—including array gain—is computed separately for each of the two (or three) polarizations using the
procedures presented in this document. The highest of the total gains shall apply.
（i）具有N = 2的交叉极化天线。在具有仅两个输出驱动一对交叉极化（例如，垂直和水平或左圆和右圆）的天线的发射机的情况下，定向增益 是单个天线的增益。 如果两个天线具有不同的增益，则适用较大的增益。
（ii）多个天线，每个天线具有彼此正交的两个（或三个）偏振中的一个（即，交叉极化）。 （如果使用三个极化，则所有三个极化必须相互正交。）使用本文档中介绍的程序，分别为两个（或三个）极化中的每一个计算总增益（包括阵列增益）。 总收益中的最高者适用。
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d) Unequal antenna gains, with equal transmit powers. For antenna gains given by G1, G2, …,
GN dBi (i) If transmit signals are correlated, then
Directional gain = 10 log[(10G1 /20 + 10G2 /20 + … + 10GN /20)2 /NANT] dBi [Note the “20”s in the denominator of each exponent and the square of the sum of terms; the object is to combine the signal levels coherently.]
(ii) If all transmit signals are completely uncorrelated, then
Directional gain = 10 log[(10G1 /10 + 10G2 /10 + … + 10GN /10)/NANT] dBi
d）不等的天线增益，具有相等的发射功率。 对于由G1，G2，...，GN dBi（i）给出的天线增益，如果发射信号相关，则
方向增益= 10log [（10G1 / 20 + 10G2 / 20 + ... + 10GN / 20）2 / NANT] dBi [注意每个指数的分母中的“20” 目标是相干地组合信号电平。 （ii）如果所有发射信号完全不相关，则
方向增益= 10log [（10G1 / 10 + 10G2 / 10 + ... + 10GN / 10）/ NANT] dBi
e) Spatial Multiplexing. In some cases spatial multiplexing is combined with techniques that
produce correlated signals, such as beamforming or cyclic delay diversity. This is common when the number transmit antennas exceeds the number of independent data streams (i.e., the number of “spatial streams”) to be transmitted. For cyclic delay diversity, see section f) below. In all other cases directional gain is calculated as follows.
CAUTION: Most devices can operate with one spatial stream (NSS = 1, where NSS is the number of spatial streams) even if they also are capable of more spatial streams. The worst case directional gain will occur when NSS = 1; therefore, it is especially important to ensure that the device complies with all emission limits for the case of NSS = 1 (or with the lowest possible value of NSS, if the device always uses spatial multiplexing). The application filing must clearly include a proper justification for the lowest value NSS used.
e）空间复用。 在一些情况下，空间复用与产生相关信号的技术（例如波束成形或循环延迟分集）组合。 当数目的发射天线超过要发射的独立数据流的数目（即，“空间流”的数目）时，这是常见的。 对于循环延迟分集，参见下面的f）部分。 在所有其他情况下，方向增益计算如下。
注意：大多数设备可以使用一个空间流（NSS = 1，其中NSS是空间流的数量）运行，即使它们也能够有更多的空间流。 最坏情况下的方向增益将发生在NSS = 1时; 因此，尤其重要的是确保设备符合NSS = 1（或者如果设备总是使用空间复用）的NSS的最低可能值的情况下的所有发射限制。 申请文件必须清楚地包括对所使用的最低值NSS的适当理由
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(i)
If all antennas have the same gain, GANT:
Directional gain = GANT + 10 log(NANT/NSS) dBi, where NSS = the number of independent spatial streams of data and GANT is the antenna gain in dBi. (This formula can also be applied when antennas have different gains if the highest antenna gain is substituted for GANT.)
(ii) If antenna gains are not equal and each transmit antenna is driven by only one spatial
stream, directional gain may be calculated by either of the following two formulas.
（i）如果所有天线具有相同的增益，GANT：
定向增益= GANT + 10log（NANT / NSS）dBi，其中NSS =数据的独立空间流的数量，GANT是天线增益（dBi）。 （如果天线增益不同，如果最高天线增益代替GANT，则该公式也可以应用）。 （ii）如果天线增益不相等并且每个发射天线仅由一个空间流驱动，则可以通过以下两个公式中的任一个来计算方向增益。
? Directional gain = GANT MAX + 10 log(NANT/NSS) dBi, where NSS = the number of independent spatial streams of data and GANT MAX is.the gain of the antenna having the highest gain (in dBi). 定向增益= GANT MAX + 10log（NANT / NSS）dBi，其中NSS =数据的独立空间流的数量，GANT MAX是具有最高增益的天线的增益（以dBi为单位）。 或者：
? NSS ?NANT ?2 ?
?∑?∑g j,k ? ? DirectionalGain =10?log??? j=1 ?Nk=1ANT ? ??? ?
?
?
?
?
where
Each antenna is driven by no more than one spatial stream; NSS = the number of independent spatial streams of data; NANT = the total number of antennas
gj,k = 10
Gk / 20
if the kth antenna is being fed by spatial stream j, or zero if it is
not; Gk is the gain in dBi of the kth antenna.
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(iii) If antenna gains are not equal and each transmit antenna can be driven by more than one spatial stream, directional gain may be calculated by either of the following two formulas.
如果天线增益不相等并且每个发射天线可以由多于一个的空间流驱动，则可以通过以下两个公式中的任一个来计算方向增益。
? Directional gain = GANT MAX + 10 log(NANT/NSS) dBi, where NSS = the number of independent spatial streams of data and GANT MAX is.the gain of the antenna having the highest gain (in dBi). Or,
? NSS ?NANT ?2 ?
?∑?∑g j,k Pj,k ? ?
DirectionalGain =10?log?? j=1 ? k=1N ANT? ???
?
?
?
?
? ? where
NSS = the number of independent spatial streams of data; NANT = the total number of antennas;
gj,k = 10k if the kth antenna is being fed by spatial stream j, or zero if it is not;
Gk is the gain in dBi of the kth antenna;
Pj,k is the relative normalized power (in linear terms, not decibels) of spatial stream j feeding the kth antenna, normalized such that
G/ 20
NSS
?NANT ?
j,k
∑?∑P
?=N ANT j=1
? k=1 ?
Note: Pj,k = 0 if spatial stream j does not feed the kth antenna.
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