Application of dominant interference cancellation in street microcells

Abstract

In street microcells, cochannel interference problem arises especially at the street intersections without base station site where interference level can go up very rapidly due to the possible line-of-sight interference. To guarantee contiguous service quality in the street crossings rather conservative reuse distances should be selected at the expense of lower system capacity. In this paper we show that at the street intersections a single interfering signal dominates suggesting that interference cancellation of the dominant interfering signal is a potential method to overcome the problem. Accordingly, we apply joint detection of the desired and dominant interfering signal in the GSM system and evaluate the potential advantage in the Manhattan microcell environment. The results indicate that this tecnique enables very low reuse distances in the future high capacity microcellular systems.

Reduced-state MIMO sequence detection with application to EDGE systems

“…Let be the "ordered" noise correlation matrix, and be its LU decomposition. We try to find the that maximizes the SNR of the first symbol to be detected (18) where is the first diagonal element of and we have used (16) (18) into (19) which is solved by simply picking the that gives the smallest . Once is obtained, we fix the first element of as , and obtain by maximizing the second post-detection SNR for all where .…”

“…In these so-called interference-limited situations, a simple white Gaussian noise model is not appropriate for the sum of all interference. In [19], a more realistic interference model is proposed where the overall interference is broken into two parts, where the first component remains white Gaussian noise and the second component is modeled as a dominant interfering base station. A parameter called dominant to rest of interference power ratio (DIR) is introduced to describe the relative power ratio of these two components.…”

An interference suppression scheme with joint channel-data estimation

“…More recently, interference suppression schemes based on sequence detection have been proposed 12,13,14,15,16,17,18]. Maximum a-posteriori (MAP) based sequence detection scheme, where both the desired signal and the interference are jointly decoded, is examined in 12,13].…”

“…Maximum a-posteriori (MAP) based sequence detection scheme, where both the desired signal and the interference are jointly decoded, is examined in 12,13]. Joint detection of the desired user with the interference has also been proposed in 14,15] where a maximumlikelihood based sequence detection scheme suitable for time-invariant channels is proposed. In this paper we do not attempt to decode the undesired users and therefore do not need to know the number of interferers or their modulation schemes.…”