We characterize the ergodic spectral efficiency of a non-cooperative and a cooperative type of K-tier heterogeneous network with limited feedback. In the non-cooperative case, a multi-antenna base station (BS) serves a single-antenna user using maximum-ratio transmission based on limited feedback. In the cooperative case, a BS coordination set is formed by using dynamic clustering across the tiers, wherein the intra-cluster interference is mitigated by using multi cell zero-forcing also based on limited feedback. Modeling the network based on stochastic geometry, we derive analytical expressions for the ergodic spectral efficiency as a function of the system parameters. Leveraging the obtained expressions, we formulate feedback partition problems and obtain solutions to improve the ergodic spectral efficiency. Simulations show the spectral efficiency improvement by using the obtained feedback partitions. Our major findings are as follows: 1) in the non-cooperative case, the feedback is only useful in a particular tier if the mean interference is small enough; 2) in the cooperative case, allocating more feedback to stronger intra-cluster BSS is efficient; and 3) in both cases, the obtained solutions do not change depending on the instantaneous signal-to-interference ratio.
|Number of pages||16|
|Journal||IEEE Transactions on Wireless Communications|
|Publication status||Published - 2018 Jun|
Bibliographical noteFunding Information:
Manuscript received August 12, 2017; revised November 21, 2017 and February 2, 2018; accepted March 11, 2018. Date of publication March 27, 2018; date of current version June 8, 2018. This work was supported in part by the National Science Foundation under Grant NSF-CCF-1319556, In part by the Institute for Information & communications Technology Promotion (IITP) under grant funded by the MSIT of the Korea government (No.2018(2016-0-00123), Development of Integer-Forcing MIMO Transceivers for 5G & Beyond Mobile Communication Systems. This paper was presented in part at the IEEE Globecom Workshop, December 2016 . The associate editor coordinating the review of this paper and approving it for publication was W. Zhang. (Corresponding author: Namyoon Lee.) J. Park is with Qualcomm Wireless Research and and Development, San Diego, CA 92121 USA (e-mail: email@example.com).
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All Science Journal Classification (ASJC) codes
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics