Mobile Computing Technologies Essay Example | Topics and Well Written Essays - 3000 words

Mobile Computing Technologies - Essay Example The capability of FHSS to resist any interference from false RF signals is supposed to be quite a number of times better than the capability of DSSS. The implementation of FSSS system is easier. A lower power density is used by DSSS. This makes the detection of DSSS harder. Another reason why DSSS is not preferred is that in order to ensure reception it sends redundant copies of encoded data. One of the implications that may be associated in this case is that the assignment would have to be within the standards set by ITU. The maximum limit of allocation cannot exceed 300GHz in accordance with the set limits as shown in Figure 2: (Roke Manor Research, n.d.) 2. The receiver system to be used is based on the Superheterodyne design. Briefly explain the principle of operation of the Superheterodyne and discuss any potential issues which may be of concern with this type of receiver design and receiver systems in general. The way Superhetrodyne receives is that it uses frequency mixing and converts its received signal into a fixed Intermediate Frequency. An If or an Intermediate Frequency is much conveniently processed than the conventional radio carrier frequency. One concern with Superhetrodyne is that along with the wanted signal it also generates an unwanted signal which is referred to as image frequency. This is a problem because it is a false response. The only way this response can be prevented by incorporating a filter that would restrict the image frequency from reaching the mixer. It has been decided that the cost of implementing a bespoke communication link is too expensive and the existing cellular infrastructure will be used. The GSM mobile unit 1.5km away is receiving a signal from the Vodafone base station transmitter on top of the Owen Building (postcode S1 1WB). When signals collided with road traffic they can cause diffraction, absorption and multipath fading. When signals collide with a material it can lose its strength and its path can be reflected and refracted thus causing a delay in receiving the signal which results in Multipath fading.