Packet loss and energy dissipation are two major challenges of designing large-scale wireless sensor networks. Since sensing data is spatially correlated, compressed sensing (CS) is a promising reconstruction scheme to provide low-cost packet error correction and load balancing. In this letter, assuming a multi-hop network topology, we present a CS-oriented data aggregation scheme with a new measurement matrix which balances energy consumption of the nodes and allows for recovery of lost packets at fusion center without additional transmissions. Comparisons with existing methods show that the proposed scheme offers higher recovery precision and less energy consumption on TinyOS.

A great deal of effort has been spent to develop strategies for allocation of resources in DS-CDMA systems in order to mitigate effects of interference between users. Here, the choice of spreading sequences and appropriate power allocation play a crucial role. When developing such strategies, CDMA system designers need to ensure that each user meets its quality-of-service requirement expressed in terms of the signal-to-interference+noise ratio. We say that a set of users is admissible in a CDMA system if one can assign sequences to the users and control their power so that all users meet their quality-of-service requirements. In [1], the problem of admissibility in a synchronous CDMA channel was solved. However, since the simplistic setting of perfect symbol synchronism rarely holds in practice, there is a strong need for investigating asynchronous CDMA channels. In this paper, we consider a K-user asynchronous CDMA channel with processing gain N and identical performance requirements for all users assuming chip synchronism. We solve the problem of admissibility of the users in such a channel if N K, and identify optimal sequences. We also show that constant power allocation is optimal. Results obtained in this paper give valuable insights into the limits of asynchronous CDMA systems.