Computer simulation of a mobile packet radio system

IEEE J. Select. Areas Commun.

Jong

Prasad

1993

Abstract-An analytical model is developed for the performance of a microcellular radio network in the presence of co-channel interference and additive white Gaussian noise. The modulation schemes considered are BPSK, BFSK, and QPSK. The multiple-access channel is statistically modeled by one Riciandistributed desired signal and several uncorrelated Rayleigh plus log-normally shadowed interfering signals, propagating according to dual path loss law with a turning point. The performance is determined in terms of bit error rate (BER), outage probability, block error probability, crosstalk probability, and spectrum efficiency, considering both fast and slow multipath fading. The effect of error correction codes, consisting of blocks with equal number of bits, on the performance parameters is also studied.The computational results show that the propagation loss exponents, Rician factor, turning point, and cell size all play a major role in the design of an efficient microcellular system. A proper compromise has to be achieved between spectrum efficiency and bit error rate. The error correction capability of BCH code has a significant effect on the performance for fast multipath fading. However, with slow multipath fading and/or severe shadowing, the effect of error correction is much smaller. Unshadowed fast multipath fading is less harmful than (shadowed or unshadowed) slow multipath fading when appropriate coding is used.

Section: Receiver Modelmentioning

confidence: 99%

“…The local-mean block error probability assuming fast multipath fading can be found by substituting directly the local-mean BER (given by (14) with a , = 0) instead of (8) in (20). Where assuming slow multipath fading, the block error probability has to be averaged over the Rician pdf (3).…”

Section: Block Error Probabilitymentioning

confidence: 99%

Effect of coding in digital microcellular personal communication systems with co-channel interference, fading, shadowing, and noise

IEEE J. Select. Areas Commun.

Jong

Prasad

1993

Near-far effects in land mobile random access networks with narrow-band Rayleigh fading channels

IEEE Trans. Veh. Technol.

Hekmat

Venema

1992

The near-far effect of random access protocols in mobile radio channels with receiver capture is investigated. To this end, the probability of successful reception of a packet from a terminal at a known distance from the central receiver is obtained taking into account Rayleigh fading, UHF propagation attenuation, and the statistics of contending packet traffic in radio nets employing slotted ALOHA, carrier sense multiple access (CSMA) or inhibit sense multiple access (ISMA) protocols. Various models of receiver capture are compared, namely packet error rates for synchronous detection in slow-and fast-fading channels, and the probability that the signal-to-interference ratio is above a required threshold.

Throughput of inhibit sense multiple access with propagation delays

Awater

Venema

1994

IEEE Trans. Commun.

Abstrut-A large number of terminals transmitting data packets over a common radio channel to a central base station is studied. In inhibit sense multiple access (ISMA), the base station broadcasts a busy signal when an incoming packet is being received, to inhibit other terminals from colliding transmissions. This busy signal arrives at each terminal with a propagation delay, proportional to the distance between the base station and the terminal. This leads to unfairness in the probability of successfully transmitting a data packet, since nearby terminals have more up-to-date information on the actual channel status than remote terminals. This unfairness is additional to the advantage that nearby terminals have because of the capture effect, which is also considered here. The paper applies nonstationary Poisson precesses to describe the random arrivals of data packets at the central receiver. It is shown that the probability of a successful attempt to transmit a packet decreases, approximately linearly with the distance between the transmitter and the central receiver. The total throughput is also assessed, and is found that the assumption of a fixed propagation delay adopted in CSMA studies by others gives too optimistic results for ISMA. Moreover, our analysis suggests a subtle change of the fixed delay approximation that enhances its accuracy, without adding complexity. The effect of propagation delays in random access radio networks are of increasing importance, since newly developed systems are designed to transmit with increasingly high bit rates.