【正文】 s developed a kind of with high potential new wireless munication technology, it was listed as one of the ten future munication technology.1 uwb wireless munication ultrawideband technology introduction UWB (the mkultra Wideband, ultrawideband) technology is currently has been widely studied a new wireless munication technology, it has bee a highspeed wireless personal nets (WPAN first choice 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 GHz, bandwidth of GHz, spectral range is very wide, but transmission power is very low. Communications speed in 250Kbit ~ between 10Mbit/SEC. In 250Kbit/SEC transmission speeds can ensure as munication distance. In short (13m below) a has great advantage, highest transmission speed can reach 1Gb/S. While the traditional narrowband technology in long distance, low speed transmission dominant.Ultrawideband (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 formally its suspension. Currently ultrawideband (UWB) technology is being integrated into the family cinema and portable products, mainly used for video and audio signal of wireless transmission. Ultrawideband (UWB) since when published has been regarded as bluetooth technology substitute, and other wireless technologies such as WLAN, bluetooth etc pared ultrawideband (UWB), with low power waste, high bandwidth and low plexity, the advantages of low cost, can pletely satisfy short family entertainment application requirements. ultrawideband performance characteristics.Uwb wireless munication 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 antijamming performance UWB signal, the launch will be weak 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 a, IEEE b and bluetooth,pared to the same code speed conditions, the UWB has a strong antijamming.2) transmission rate is high UWB with very wide frequency bandwidth for highspeed data transmission, and not alone occupy now already crowded frequency resource, but sharing other wireless technology using frequency band. The data rate can reach dozens megabit per second to hundreds of megabit per second, is expected to 100 times higher than bluetooth, also can prep above IEEE and IEEE . 3) with very wide bandwidth UWB use of bandwidth in 1GHz above, up to a few ji hz and can and current narrowband munication system working at the same time and not interfere with each other. This in frequency resource of increasingly scarce today opened up a new timedomain radio resources. 4) spectrum is high efficiency, the system of large capacity Because it does not need to produce sine carrier signal that can be directly launch impulse 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 capacity. 5) low power Ultra wideband (UWB) technology use intermittent pulses to send data, pulse lasted for a very short time, is in monly ns ~ ns between, have very low accounted for empty factor, the system power consumption can be done very low, in high speed munications system when consume only for hundreds of muon W ~ dozens mW. At the same time because ultra wideband (UWB) technology of spread spectrum signal processing is relatively large, even if the gain USES low gain omnidirectional antenna with emission, also can use less than 1mW launch power realization thousands of meters of munication. 6) good safety UWB safety performance in two aspects: one is to adopt the jump spread spectrum, receiver only known the sender spread spectrum yards to work out emission data。 otherwise, the station must wait until the current transmission is plete before transmitting. The DCF does not include a collisiondetection function (., CSMAICD) because collision detection is not practical on a wireless network. The dynamic range of the signals on the medium is very large, so that a transmitting station cannot effectively distinguish ining weak signals from noise and the effects of its own transmission. To ensure the smooth and fair functioning of this algorithm, DCF includes a set of delays that amounts to a priority scheme. Let us start by considering a singledelay known as an interframe space (IFS). In fact, there are three different IFS values, but the algorithm is best explained by initially ignoring this detail. Using an IFS, the rules for CSMA access are as follows:I. A station with a frame to transmit senses the medium. If the medium is idle, the station waits to see if the medium remains idle for a time equal to IFS, and, if this is so, the station may immediately transmit.2. If the medium is busy (either because the station initially finds the medium busy or because the medium bees busy during the IFS idle time), the station defers transmission and continues to monitor the medium until the current transmission is over.3. Once the current transmission is over, the station delays another IFS. If the medium remains idle for this period, then the station backs off using a binary exponential backoff scheme and again senses the medium. If the medium is still idle, the station may transmit.Point Coordination Fu