With the increasing use of short-range wireless devices for high-data-rate communication in the shared frequency bands, the level of interference can be expected to increase. The ability to estimate the performance degradation of these devices due to increasing interference is, therefore, important. In this paper, the throughput of devices that perform frequency hops after each transmitted packet in order to achieve diversity is investigated. The system model allows for an analysis of systems where packets of variable durations are used, and the throughput derivation is based on the assumption that collisions result in a total loss of the data in the colliding packets. The resulting expression for the throughput is given as a function of the number of frequency channels used for frequency hopping, the number of interfering networks, the durations of the packet types available, and the probability of networks selecting a certain packet type for transmission. An approximation of the exact expression for the throughput is also derived, and the results are applied to an example system consisting of Bluetooth piconets.

The impact of the quantization of SNR measurements on the throughput of a multiuser diversity scheme for constant-rate transmission is investigated under a block-Rayleigh fading assumption. In the downlink, each user measures its SNR, quantizes it, and feeds it back to the transmitter, which transmits a packet to the user with the highest quantized SNR. In the case of several users having the same quantized SNR, one of them is selected at random. It is concluded that using only a few quantization levels can yield a throughput that is only slightly less than the throughput obtained by using unquantized feedback.

The impact of interference from Bluetooth networks on the throughput of IEEE 802.11 FHSS networks is investigated. This is done by deriving an analytical approximation of the throughput of slow frequency-hopping systems. The derivation in itself provides valuable insights into the mechanisms of interference between systems employing the frequency-hopping technique. In deriving the approximation, it is assumed that packet collisions result in total loss of all information contained in the packets involved in the collisions, regardless of the distance between the networks. The results indicate that the Bluetooth networks may have a negative effect on the throughput of an IEEE 802.11 network using long packet types.