Evaluation of overall outage probability in cellular systems

Abstract

A new method f o r the evaluation o f the o v e r a l l outage p r o b a b i l i t y i n c e l l u l a r mobile r a d i o i s proposed. This method involves both l i n k s , i.e. M->B (Mobile-to-Base) and B->M (Base-to-Mobile), t a k i n g i n t o account the j o i n t e f f e c t s o f co-channel and adjacent channel i n t e r f e r e n c e s , t h e net f i l t e r d i s c r i m i n a t i o n , the r a d i a t i o n p a t t e r n s o f the base s t a t i o n antennas, the power c o n t r o l c h a r a c t e r i s t i c , the t r a f f i c d i s t r i b ut i o n , and some t y p i c a l propagation phenomena o f the mobile r a d i o environment, such as shadowing e f f e c t s .

A new cellular architecture based on an interleaved cluster concept

“…We have (4) where is the received power from the th individual interferer and is the number of active cochannel interferers. 1 For a given air interface, if the required (or threshold) value of SIR for good reception is , then ) is the coverage probability, or reliability, for that interface, and is the outage probability. Assuming that all sectors transmit at the same power, the SIR for a given user can be expressed as (5) where is the angles to the main beam of a directional antenna, is the antenna gain at angle in decibels, is the distance of the th interferer to the user, is the shadow fading variable [10 is a Gaussian random variable with zero mean and standard deviation ], the subscript 0 corresponds to the user (desired signal), and are the indexes for the active cochannel interferers.…”

“…A newer cellular architecture used in some second generation digital cellular systems, such as the global systems for mobile telecommunications (GSM's) and IS-136, is the narrow-beam trisector cell (NBTC). An NBTC (also called a clover-leaf cell [1]) is composed of three 60 to 70 directional antennas (see Fig. 2).…”

A new cellular architecture based on an interleaved cluster concept

“…4-6, respectively, where the NBTC and WBTC systems have a reuse factor , and the INBTC system has a reuse factor . To maintain the same separation between two adjacent cell sites for the three systems, we have the following relationship among the cell radii of the three architectures: (1) where and are the cell radius of the INBTC, NBTC, and WBTC, respectively. Because of this radius difference, to maintain the same received signal strength at the farthest points of an NBTC and a WBTC with the same transmitting power, the base station in an NBTC system needs about 2.5-dB higher antenna gain than that in the WBTC system, assuming a path-loss exponent .…”

“…We have (4) where is the received power from the th individual interferer and is the number of active cochannel interferers. 1 For a given air interface, if the required (or threshold) value of SIR for good reception is , then ) is the coverage probability, or reliability, for that interface, and is the outage probability. Fig.…”