umts the fundamentals

[...]... means that the carrier has to be received at six times the strength of the aggregate of the interference signals The minimum values for the CIR are dependent on many factors, such as the type of receiver used, the modulation method, and the channel coding The aggregate of the carrier signal of power C and the interference signal of power I arrive at the receiver The higher the interference power, the more... understand the relationship between the distance and the propagation attenuation of radio waves The further away a receiver is located from a transmitter, the smaller the portion of the emitted power that arrives at the receiver (see Figure 2.4) A number of mathematical models describe this dependency The exact relationship depends on the frequency range, the type of antennas used, the condition of the environment,... that the greater the received signal strength, the smaller the chance of error frequency The width of the Gaussian distribution is proportional to the noise power This means that the greater the noise power, the higher is the error probability and vice versa Thus, the error probability increases proportional to the noise power and decreases proportional to the signal power One measurement of the quality... and cluster formation The distance between two cells that are allocated the same frequency is called the reuse distance The smaller the reuse distance, the closer the cell in which the frequency is reused This cell is also called co-channel cell The closer co-channel cells are located to a cell, the more they will cause interference to communication in the cell Network operators therefore have a considerable... Preface to the system architecture, the various network elements and the protocols used in the UMTS fixed core network The keys to the commercial success of UMTS are new services that are not available with the existing mobile radio systems This is why we introduce future service architectures and services for UMTS that have already been experimented with in the GPRS Further, we describe the development... sensitive The / in the denominator of the equation is the total interference /„ that occurs in the receiver from other stations If one considers the uplink (mobile station sends, base station receives), the sources of interference are mobile stations that are active in other cells and transmit from there The radio waves transmitted there are also received as interference at base stations outside the cell... indicator of the received signals quality For the so-called carrier-to-interference ratio C/I applies the same as for the signal-to-noise ratio: the higher the wanted signal's power (carrier) and the lower the interference power the lower is the bit error probability, see Chapter 2 If data transmission is only noisy due to Gaussian noise, then the transmission capacity of such a channel is dependent on the. .. consequently the overall CIR is too low The frequency of transmission errors becomes too high, and in turn, the connection gets noisy or even cut off This situation can even occur if there is no interference at all, because the coverage areas of the cells are limited and the thermal noise in the receiver limits the range of the cells This kind of system is called range limited The second case occurs when the. .. message transmission, i.e., for the error frequency, is therefore the ratio of the received signal strength to the noise power, also referred to as S/N ratio The greater this ratio, the smaller the probability of transmission error; thus achievable throughput is proportional to the S/N ratio In network engeneering, the ratio between the received wanted carrier signal power and the sum of all received interference... because other senders other than the user that are also emitting energy in the same frequency band Since co-channel cells always exist in cellular radio networks, interference is inherent to these networks The level of interference depends, among other things, on the distance between the receiver and the jamming transmitters This is directly dependent on the reuse distance If all subscribers use the same . After that, chapters on the transmission technique and the proto- cols of the UMTS air interface follow. Later sections of the book are devoted UMTS: The Fundamentals B. Walke, . Ltd X Preface to the system architecture, the various network elements and the protocols used in the UMTS fixed core network. The keys to the commercial success of UMTS are new . a measurement of the voltage at the end of the circuit shows that changes are slower rather than abrupt. The circuit then has the effect of a pulse former, the signal is changed