Frameless ALOHA with multiple base stations

We propose frameless ALOHA with multiple base station (BS) cooperation; each user transmits a packet with the shared access probability calculated by a target degree and the BSs cooperatively decode the information from whole received packets using successive interference cancellation. An exact analysis scheme on the decoding error probability of the proposed system is established and the constant target degrees are optimized so that the average throughput is maximized. Numerical results reveal that cooperation among BSs results in much higher throughput than the original frameless ALOHA and optimized target degree provides the further performance improvement. Also, we consider the use of multiple degrees with probability mass function, namely degree distribution, in frameless ALOHA and show that multiple target degrees does not provide large gain compared with the constant degree distribution.