Interference coordination for LTE-Advanced and FM broadcasting interoperability

Abstract

The surest way to guarantee that multiple wireless systems can concurrently exist harmlessly, when operating in the same or adjacent channel, is by analyzing spectrum overlapping. This paper proposes a more accurate model to evaluate the interference power from co-channel and adjacent channel of orthogonal frequency division multiplexing-based long term evolution-advanced (LTE-Advanced) towards broadcasting frequency modulation systems at 800 MHz. Power spectral density overlapping factor is employed, and closed form of the interference power loss is derived. Numerical results demonstrate that the proposed method evaluates more exact interference power than the advanced minimum coupling loss (A-MCL) method, where the co-channel and adjacent channel interference powers are reduced by 1.3 and 3 dB, correspondingly, compared to that obtained using the A-MCL method. This decreases the minimum separation distance between the two systems, which can eventually lead to efficient radio spectrum resources utilization.

A Graphical Method for LTE-A System and Digital Broadcasting Interoperability Studies

“…On the other side, if the power level of LTE-A is higher than the minimum level and the difference between desired signal and interference signal is not high enough, LTE-A can cause harmful interference on TV receiver. The interference power level, I (dBm) can be expressed by the following equation [6], [17]:…”

“…Consequently, ITU-R has recently decided to be utilized by IMT-A systems in the Regions 1 (Europe, Africa and Arab countries) and 3 (Asia). In addition, the ITU recommended the 790-862 MHz band to be engaged by a number of dissimilar services including digital broadcasting service, on co-primary basis [6]. This co-primary operation between LTE-A and broadcasting receiver may cause destructive interference between the two services [7,8] and can affect on the system performance [9][10][11].…”

An Improved Mathematical Scheme for LTE-Advanced Coexistence with FM Broadcasting Service

“…However, A-MCL is not suitable for studying the interference from OFDM-based systems into Frequency Modulation (FM) broadcasting service that has a triangular power spectral density (PSD) shape [9, 10, 20, 21]. Therefore, the approximate-interference signal power attenuation (ISPA) method is derived by [9, 10] to evaluate interference from IMT-Advanced systems to FM broadcasting.…”

“…We propose this method due to that the approximate-interference signal power attenuation (ISPA) method [9, 10] uses approximation calculations of LTE-Advanced interference power into FM service which causes overestimation of the interference. In contrast, this proposed method is more accurate than the existing schemes [9–12] as it takes into account realistic shapes of the interferer and victim signals.…”

“…However, the ISPA method uses bandwidth overlap factor which is computed by multiplying of PSD of the transmitter and PSD of the receiver to investigate coexistence situation [11, 12, 14–15]. The result of the bandwidth overlapping factor is a spectral emission mask but it considers PSD of both the transmitter and the receiver [10]. In this method the size of overlapping area between the interferer and the victim plays an important role in estimating the power loss due to overlapping.…”