超宽带技术与其它短距离无线通信技术的比较

1、超宽带技术与其它短距离无线通信技术的比较随着个人通信消费电子产业的迅猛开展， 短距离无线通信领域的各种新技 术、 新方法层出不穷，朝着更快、更方便、更平安有效等方面进行开展。新的技术在 Intel 接入、信息家电、移动办公、工业化等各个领域得到了广泛的运用。其中，超宽带 Ultra Wide Band, UWB 技术是在 20世纪 90年代以后开展起 来的一 种具有巨大开展潜力的新型无线通信技术，被列为未来通信的十大技术之O1 超宽带无线通信1.1 超宽带技术简介UWB Ultra Wideband,超宽带技术是日前正被广泛研究的一种新兴无线通信技术，现在已经成为高速无线个人网 WPAN 的首

2、选技术。UWB 是指信号带宽大于 500MHz 或者是信号带宽与中心频率之比大于 25%的 通信技术。与常见的通信方式使用连续的载波不同， UWB 中使用的无线信号中心 频率为4.1GHz,带宽为1. 4GHz濒谱X圉很宽，但是发射功率非常低。通信速 度 在250Kbit? 10Mbit/秒之间。在250Kbit/秒的传输速度下可确保30m的通信 距离。 在短距离13m以下有很大优势，最高传输速度可达lGb/S。而传统 的窄带技术在长距离、低速传输具有优势。超宽带UWB技术最初是面向雷达应用来开发的，一般认为它属于一种无 载波通信技术。2002年2月，美国联邦通信委员会 FCC正式将其解禁。L

3、I前 超宽带 UWB 技术正被整合进家庭影院和便携式产品，主要用于视频和音频信号的无线发送。宽带UWB自问世后一直被看作是蓝牙技术的替代品，与其他无线技术如 WLAN 、蓝牙等相比，超宽带 UWB 具有低功耗、高带宽、 低 复杂度、低本钱的优点，完全可以满足短距离家庭娱乐应用需求。 1.2 超宽 带性 能特点。超宽带无线通信是一种与传统技术有很大不同的无线通信技术。它能够实现 无线局域网 LAN 和个人区域网 PAN 中无线接口的互联和接入。 UWB 具有以下特 占?八、?1 抗干扰性能强UWB 信号，在发射时将微弱的无线电脉冲信号分散在宽阔的频带中，输出功 率甚至低于普通设备产生的噪声。接收

4、时将信号能量复原出来，在解扩过程中产 生扩频增益。因此，与 IEEE 802. 11a 、IEEE 802. lib 和蓝牙相比，在同等码速 条 件下， UWB 具有更强的抗干扰性。2) 传输速率高UWB 以非常宽的频率带宽来换取高速的数据传输， 并且不单独占用现在已经 拥挤不堪的频率资源，而是共享其他无线技术使用的频带。其数据速率可以到达 儿十兆比特每秒到儿百兆比特每秒，有望高于蓝牙 100倍，也可以高于 IEEE 802. 11a 和 IEEE 802. llbo3) 带宽极宽UWB 使用的带宽在 1GHz 以上，高达儿吉赫兹，并且可以和口前的窄带通信 系统同时丄作而互不干扰。 这在频率资

5、源日益紧 X 的今天开辟了一种新的时域无 线电资源。4) 频谱利用率高，系统容量大因为不需要产生正弦载波信号， 可以直接发射冲激序列， 因而 CWB 系统具 有 很宽的频谱和很低的平均功率， 有利于与其他系统共存， 从而提高频谱利用率 , 带 来了极大的系统容量。5) 功率低UWB 系统使用间歇的脉冲来发送数据，脉冲持续时间很短，一般在0. 20ns?l.ons 之间，有很低的占空因数，系统耗电可以做到很低，在高速通信时系统的耗电量仅为儿白口 W? 儿十 mwo 同时山于 UWB 系统信号的扩频处理增益比较 大， 即使采用低增益的全向天线发射，也可使用小于 lmW 的发射功率实现儿千 米的 通

6、信。6) 平安性好UWB 平安性表现在两方面： 一方面是采用跳时扩频， 接收机只有发送端 扩频码时才能解出发射数据；另一方面是系统的发射功率谱密度极低。有用信息 完全淹没在噪声中，被截获概率很小，被检测的概率也很低，用传统的接收机无 法接收。2 Wi-Fi 2. 1 Wi-Fi 技术简介Wi-Fi (Wireless Fidelity, 无线高保真 ) 也是一种无线通信协议 , 正式名 称是 IEEE802. llboWi-Fi 是以太网的一种无线扩展，肌 -Fi 网络可以使用来互连电脑上互连 网。Wi-Fi网络在无执照的2.4和5千兆Hz的无线电频带经营，数据速率 可达11Mbps (802

7、.11b) "54Mbps (802. 11a),或包含以上两条频带的产品。理 论上只要用户位于一 个接入点四周的一定区域内，就能以最高约UMb/s的速度接入Web。但实际上， 如果有多个用户同时通过一个点接入，带宽被多个用户分 享。由于 Wi-Fi 使用电波作为传送媒介，资料包被截取的可能性高，这成为 用户 所担忧问题。现在 Wi-Fi 产品利用 WED (Wired Equivalent Privacy) 技 术作资料加密 之用。然而，其 XX 的效能却倍受质疑，支援新一代加密方式的 Wi-Fi 产品亦相 继出现。虽然 Wi-Fi 在数据平安性方面比蓝牙技术要差一些， 但在电波的

8、覆盖 X 围方面却略胜一筹，可达 100 m 左右。Wi-Fi 可以提供热点覆盖、低移动性和高数据传输速率，无线接入和高速 传 输是 Wi-Fi 技术的主要特点。国内的电信、网通、移动都非常关注 Wi-Fi 技 术的 开展和应用。基于热点的接入效劳曾经一度被看成是对 3G的巨大冲击，但 Wi-Fi 技术传输距离短和信号穿透能力差的特点同样也是不可克服的。2. 2 Wi-Fi 技术的优势近儿年， WAP 的数量呈迅猛增长， 无线网络的方便与高效使其得到迅速的普 及。无论是无线城市的建设， 还是企事业单位局域网的开通， 还是 的 Wi-Fi 功 能，都与 Wi-Fi 技术自身的优势是分不开的：1)

9、 较广的局域网覆盖 X 围基于蓝牙技术的电波覆盖 X围非常小，半径大约只有15m,而Wi-Fi的半 径 那么可达 100 m ,可以覆盖整栋办公大楼；2) 传输速度快Wi-Fi技术传输速度非常快，可以到达 11Mbps (802. lib)或者54Mbps(802. 11a),适合高速数据传输的业务；3) 无需布线Wi-Fi 最主要的优势在于不需要布线， 可以不受布线条件的限制， 因此非常 适 合移动办公用户的需要。在机场、车站、咖啡店、图书馆等人员较密集地方设 置 “热点， 并通过高速线路将因特网接入上述场所。 用户只要将支持无线 LAN 的 笔记本电脑或 PDA 拿到该区域内，即可高速接入

10、因特网；4) 健康平安IEEE802. 11规定的发射功率不可超过 100毫瓦，实际发射功率约 60? 70 毫瓦， 而 的发射功率约 200毫瓦? 1瓦间，手持式对讲机高达 5瓦。与后者 相比, Wi-Fi 产品的辐射更小。3 结论每一种无线通信方式都有其独特之处， 超宽带技术传输速率高， Wi-Fi 技术 覆 盖 X 围广。随着无线通信技术的开展， 人们对高速短距离无线通信的要求越来 越 高，超宽带技术、 Wi-Fi 技术都有着广泛的开展前景。UWB technology and other short-range wireless munications technology is pa

11、redAs personal munication consumer electronics industry in the rapid development, short-range wireless munication field of all kinds of new skills ,art, new methods to emerge in endlessly, toward faster and more convenient and more safe and effective etc. The new technology in the development of the

12、 Intel access, information home appliances, mobile office, industrialization and other fields has been widely used. Among them, ultra-wideband (UWB) Wide Band, the mk-ultra technology is in after 1990*s developed a kind of with high potential new wireless munication technology, it was listed as one

13、of the ten future munication technology.1 uwb wireless municationLI ultra -wideband technology introductionUWB (the mk-ultra Wideband, ultra -wideband) technology is currently has been widely studied a new wireless munication technology, it has bee a high-speed wireless personal nets (WPAN first cho

14、ice of the technology. UWB refers to the signal bandwidth than 500MHz or is the signal bandwidth and center frequency ratio is more than 25% of munications technologies? With the mon use of continuous carrier munication mode is different, use of UWB wireless signals center frequency 4.1 GHz bandwidt

15、h of 1.4 GHz, spectral range is very wide, but transmission power is very low. munications speed in 250Kbit between lOMbit/SEC ? In 250Kbit/SEC transmission speeds can ensure as munication distance. In short (13m below) a has great advantage, highest transmission speed can reach lGb/S? While the tra

16、ditional narrowband technology in long distance, low speed transmission dominant.Ultra-wideband (UWB) technology is initially applied to develop the radar oriented, it is generally thought that it belongs to a kind of carrierless munications technologies. February 2002, the United States the FCC for

17、mally its suspension. Currently ultra-wideband (UWB) technology is being integrated into the family cinema and portable products, mainly used for video and audio signal of wireless transmission. Ultra ? wideband (UWB) since when published has been regarded as bluetooth technology substitute, and oth

18、er wireless technologies such as WLAN, bluetooth etc pared ultra-wideband (UWB), with low power waste, high bandwidth and low plexity, the advantages of low cost, can pletely satisfy short family entertainment application requirements. 1.2 ultra-wideband performance characteristics ?Uwb wireless mun

19、ication is a very different to the traditional technology of wireless munication technology. It can realize the wireless LAN LAN and personal regional network PAN wireless Internet and access interface. UWB has the following features:1) strong anti-jamming performanceUWB signal, the launch will be w

20、eak radio pulse signal scattered on the broad band, output power and even lower than ordinary equipment of the noise? Received will signal energy reduction out, in the solution enlarge produced during spread spectrum gain. Therefore, and IEEE 802? 11 a, IEEE 802? 11 b and bluetooth.pared to the same

21、 code speed conditions, the UWB has a strong anti-jamming?2) transmission rate Is highUWB with very wide frequency bandwidth for high-speed data transmission, and not alone occupy now already crowded frequency resource, but sharing other wireless technology using frequency band? The data rate can re

22、ach dozens megabit per second to hundreds of megabit per second, is expected to 100 times higher than bluetooth, also can prep above IEEE 8021 a and IEEE 802.11 b.3) with very wide bandwidthUWB use of bandwidth in 1GHz above, up to a few ji hz and can and current narrowband munication system working

23、 at the same time and not interfere with each other. This in frequency resource of increasingly scarce today opened up a new time-domain radio resources?4) spectrum is high efficiency, the system of large capacityBecause it does not need to produce sine carrier signal that can be directly launch imp

24、ulse sequence, thus ultra wideband (UWB) technology has a wide spectrum and very low average power, which is beneficial to coexist with other systems, so as to improve the frequency spectrum utilization rate, which brings a lot of system capacit y.5) low powerUltra wideband (UWB) technology use inte

25、rmittent pulses to send data, pulse lasted for a very short time, is in monly 0.20 ns ? 1.5 ns between, have very low accounted for empty factor, the system power consumption can be done veiy low, in high speed munications system when consume only for hundreds of muon W ? dozens mW. At the same time

26、 because ultra wideband (UWB) technology of spread spectrum signal processing is relatively large, even if the gain USES low gain omni-directional antenna with emission, also can use less than lmW launch power realization thousands of meters of municat ion ?6) good safetyUWB safety performance in tw

27、o aspects: one is to adopt the jump spread spectrum, receiver only known the sender spread spectrum yaids to work out emission data; On the other hand is the transmission power spectral density is extremely low. Useful information pletely submerged in noise, be intercept probability is small, be det

28、ection probability is low, with traditional receiver cannot receive?2 Wi ? Fi2.1 Wi - Fi technology introductionWi - Wireless Fidelity, Wireless Fi (high-fidelity) is a kind of Wireless niunication protocol, official name is IEEE802.11 b.Wi ? Fi is Ethernet a wireless expand. Wi - Fi network can use

29、 to interconnect puter links on the Internet. Wi - Fi network in no license 2.4 and 5 gigabit bandwidth management, Hz radio data rate can reach 11Mbps (802.11 b)? 54Mbps (802.11 a), or include the above two bands of products? If the user is located in an access point theoretically around certain re

30、gion, can with highest about 11 Mb/s faster access Web? But in fact, if there are multiple users at the same time through a point access, bandwidth by multiple users to share.Because Wi - Fi use waves as transmission medium, material package to be intercepted tall, this be the possibility of users a

31、re worried about problems. Now Wi - Fi product use Wired Equivalent without (WED) technology data encryption purposes. However, its performance is highly confidential scepticism, support the new generation encryption method Wi - Fi products also arise. Although Wi - Fi in data security than bluetoot

32、h technology will send some, but in waves coverage was slightly better, can amount to 100 m or so.Wi - Fi may provide hot coverage, low mobility and high speed of data transmission, wireless access and transmission with high speed is Wi - Fi technical main characteristics.Domestic telemunication, C,

33、 mobile are very concerned Wi ? Fi technology development and application. Based on the hotspot access service once considered the huge impact on 3G, but Wi ? Fi technology transmission distance is short and signals penetrate the characteristics of poor ability also insurmountable.2.2 Wi - Fi techni

34、cal superiorityIn recent years, the number of WAP at a rapid pace, wireless network convenience and efficient make its rapid popularization. Whether wireless urban construction, or business unit of LAN opening, or mobile phones Wi ? Fi function, all with Wi - Fi technical advantages of itself is not divided:1) wider LAN coverageBased on bluetooth radio coverage is very small, radius, and only about 15m Wi - Fi radius criterion of up to 100 m. can cover whole building office building,2) transmission speedWi ? Fi technology transmission is very fast, can achieve 11Mbps (802.11 b) or 54Mbps (80