Diversity-Multiplexing Tradeoff for Multi-Connectivity and the Gain of Joint Decoding

Multi-connectivity is considered to be key for enabling reliable transmissions and enhancing data rates in future wireless networks. In this work, we quantify the communication performance by the outage probability and the system throughput. We establish a remarkably simple, yet accurate analytical framework based on distributed source coding to describe the outage probability and the system throughput in dependency on the number of links, the modulation scheme, the code rate, the bandwidth, and the received signal-to-noise ratio (SNR). It is known that a tradeoff exists between the outage probability and the system throughput. To investigate this tradeoff we define two modes to either achieve low outage probabilities or high system throughput which we refer to as the diversity and the multiplexing mode, respectively. For the diversity mode, we compare three signal processing schemes and show the SNR gain of joint decoding in comparison to maximum selection combining and maximum ratio combing while achieving the same outage probability. We then establish a diversity-multiplexing tradeoff analysis based on time sharing between both modes. Additionally, we apply our analytical framework to real field channel measurements and thereby illustrate the potential of multi-connectivity in real cellular networks to achieve high reliability or high throughput. Index Terms Distributed source coding, diversity-multiplexing tradeoff, joint decoding, multi-connectivity, outage probability.