1
ONE
(1)The
radio
age
began
over
a
100
years
ago
with
the
invention
of
the
radiotelegraph
by
Guglielmo
Marconi
and
the
wireless
industry
is
now
set
for
rapid
growth
as
we
enter
a
new
century
and
a
new
millennium.
The
rapid
progress
in
radio
technology
is
creating
new
and
improved services at lower costs, which results in increases in air-time usage and the number of
subscribers. Wireless industry revenues are currently growing between 20% and 30% per year, and
these broad trends are likely to continue for several years.
椹彲灏煎湪
100
骞村墠鏃犵嚎鐢垫姤鐨勫彂鏄庡紑鍚簡鏃犵嚎鐢垫椂浠ｏ紝
鐜板湪鏃犵嚎鐢佃涓氱殑蹇�熷闀胯璁や负鎴?/p>
浠繘鍏ヤ簡鏂颁笘绾拰鏂板崈骞寸殑鏃朵唬銆?/p>
鏃犵嚎鎶�鏈殑蹇�熷彂灞曟槸浠ヨ緝浣庣殑鎴愭湰鍒涢�犳柊鐨勫拰鏀硅繘鐨勬湇
鍔★紝浠庤�屽鍔犱簡鍦ㄦ椂闂翠笂鐨勪娇鐢ㄩ噺鍜岀敤鎴蜂娇鐢ㄧ殑鏁伴噺銆傛棤绾跨數琛屼笟鐨勬敹鍏ョ洰鍓嶆瘡骞翠互
20%
鍒?/p>
30%
鐨勯�熷害澧為暱锛岃�岃繖浜涘ぇ鐨勮秼鍔垮彲鑳戒細鎸佺画鍑犲勾銆?/p>
(2)
Multiple
access
wireless
communications
is
being
deployed
for
both
fixed
and
mobile
applications.
In
fixed
applications,
the
wireless
networks
provide
voice
or
data
for
fixed
subscribers.
Mobile
networks
offering
voice
and
data
services
can
be
divided
into
two
classes:
high mobility, to serve high speed vehicle-borne users, and low mobility, to serve pedestrian users.
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鏁版嵁涓氬姟銆?/p>
绉诲姩缃戠粶鎻愪緵鐨勮闊炽�?/p>
鏁版嵁涓氬姟琚垎涓轰袱绫伙細
楂橀�熺Щ鍔ㄦ�э紝
涓洪珮閫熻溅杞界敤鎴锋湇鍔★紱
浣庣Щ鍔ㄦ�э紝涓鸿浜虹敤鎴锋湇鍔°�?/p>
(3) Wireless system designers are faced with a number of challenges. These include the limited
availability
of
the
radio
frequency
spectrum
and
a
complex
time-varying
wireless
environment
(fading
and
multipath).
In
addition,
meeting
the
increasing
demand
for
higher
data
rates,
better
quality of service (QoS), fewer dropped calls, higher network capacity and user coverage calls for
innovative techniques that improve spectral efficiency and link reliability.
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鏃犵嚎绯荤粺鐨勮璁′汉鍛橀潰涓寸潃涓�绯诲垪鎸戞垬銆?/p>
姝ゅ锛?/p>
婊?/p>
瓒虫洿楂樼殑鏁版嵁閫熺巼鐨勯渶姹傛棩鐩婂鍔狅紝鏇村ソ鐨勬湇鍔¤川閲忥紙鏈嶅姟璐ㄩ噺锛?/p>
锛屾洿灏戠殑鎺夌嚎闂锛屼互鍙?/p>
杈冮珮鐨勭綉缁滃閲忓拰鐢ㄦ埛瑕嗙洊瑕佹眰鍒涙柊鐨勬妧鏈紝
杩欎簺鍒涙柊鎶�鏈兘瑕佹彁楂橀璋辨晥鐜囧拰閾捐矾鍙潬鎬с�?/p>
(4) Wireless system designers are faced with a number of challenges. These include the limited
availability
of
the
radio
frequency
spectrum
and
a
complex
time-varying
wireless
environment
(fading
and
multipath).
In
addition,
meeting
the
increasing
demand
for
higher
data
rates,
better
quality of service (QoS), fewer dropped calls, higher network capacity and user coverage calls for
innovative techniques that improve spectral efficiency and link reliability.
鏃犵嚎绯荤粺璁捐浜哄憳闈复鐫�璁稿鎸戞垬锛?/p>
杩欎簺鎸戞垬鍖呮嫭鏃犵嚎鐢甸璋辩殑鏈夐檺鍙敤鎬у拰澶嶆潅鐨勬椂鍙樻棤
绾跨幆澧冿紙琛拌惤鍙婂寰勶級
銆傛澶栵紝闇�瑕佹洿濂界殑鏈嶅姟璐ㄩ噺锛屾洿灏戠殑鎺夌嚎锛屾洿楂樼殑缃戠粶瀹归噺鍜屾敼鍠?/p>
棰戣氨鏁堢巼鍜岄摼璺彲闈犳�у垱鏂版妧鏈潵鎻愬崌缃戠粶瀹归噺鍜岀敤鎴风殑瑕嗙洊鏉ユ弧瓒宠秺鏉ヨ秺楂樼殑鏁版嵁閫熺巼
鐨勯渶姹傘�?/p>
(5)
The
origins of
radio
date
back
to 1861
when
Maxwell,
while
at
King鈥檚
College
in
London,
proposed a mathematical theory of electromagnetic (EM) waves. A practical demonstration of the
existence
of
such
waves
was
performed
by
Hertz
in
1887
at
the
University
of
Karlsruhe,
using
stationary (standing) waves. Following this, improvements in the generation and reception of EM
waves were pursued by many researchers in Europe.
骞挎挱鏄竴绉嶇數纾佹尝鐨勬暟瀛︾悊璁猴紝瀹冪殑璧锋簮鍙互杩芥函鍒伴害鏂▉灏斿湪浼︽暒鍥界帇瀛﹂櫌鐨?/p>
1861
骞淬�?/p>
1887
骞达紝
璧吂浣跨敤鍥哄畾
锛堢珯绔嬶級
娉㈠湪鍗″皵鏂瞾鍘勫ぇ瀛﹀垏瀹炲彲琛岀殑璇佹槑浜嗚繖绉嶆尝銆?/p>
鍦ㄦ涔嬪悗锛?/p>
璁稿娆ф床鐨勭爺绌朵汉鍛樼户缁敼杩涚數纾佹尝鐨勪骇鐢熷拰鎺ユ敹銆?/p>
(6)
In 1890, Branly in Paris developed a 鈥渃oherer鈥?nbsp;that could detect the presence of EM waves