Analysis of Net SISO-SFN and MISO-SFN Gains in Single Frequency Broadcast Network

This thesis concentrates on formulating the net single frequency network gain (SFNG), an essential element for the single frequency network (SFN) service coverage prediction, from a theoretical point of view. There are two types of SFN: single-input single-output SFN (SISO-SFN) and multiple-input single output SFN (MISO-SFN). In the SISO-SFN, all transmitters send the same signal, and the gain is obtained by aggregating the energy of the receive signals and the loss is caused by the erasure effect as a function of the power imbalance. In the MISO-SFN, the transmitters send a distributed space-time encoded signal, and the diversity gain is additionally obtained, and the loss is caused by the self-interference as a function of the delay spread. From the channel impulse response (CIR) measured at each reception point, the input parameters for the formula such as the erasure probability and/or the delay spread are deduced. Consequently, the net SFNG is derived as a closed-form formula reflecting these parameters. Finally, the validity of the derived formula is confirmed by comparing the numerical analysis results with the measurement data from related previous works. Further, we exemplify a practical application of the derived formula to predict the net SFNG by using a reference network, thus confirming that the formula can be applied to practical terrestrial broadcasting environments. The capability of orthogonal frequency-division multiplexing (OFDM) to overcome multi-path interference within the guard interval allows distributing a signal over all transmitters in a terrestrial broadcast network using the same frequency. In such an SFN, the useful signal at a receiver is the superposition of all signals coming from those transmitters that distribute the required signal. An SFN provides a unique characteristic of a digital broadcasting system. In a multiple frequency network (MFN) widely used in analog broadcasting systems, a transmitter forms a service coverage area which is mainly predicted by calculating the path loss between the transmit and receive points. However, in the SFN, multiple transmitters form a service coverage area, and a receive signal overlapping area is inevitably formed so that the gain and the loss, i.e., the net gain due to the superimposed signals at the overlapping area, need to be considered in the prediction and evaluation of the SFN service coverage. Unfortunately, most of the results on SFN gain have been collected and collated by a disparate range of laboratory experiments and field measurement campaign so far. Because the SFNG is the result of factors working together, and the results obtained by heuristic approaches are affected by the experiments conditions, test methods, and measurement environment, it is quite difficult to identify the effect of the individual factors by observing only the phenomenon. Therefore, developing a theoretical closed-form formula is required for ensuring stable and consistent SFNG calculation.