Communication on the Move with Satellite Digital Beamforming
Abstract
In a satellite communication system, channel coefficients from multiple-input-multiple-output (MIMO) antennas are correlated strongly because of a long propagation distance and a narrow angle spread. This is referred to as a keyhole (KH) channel, which results in a rank deficiency in the MIMO channel, and reduction of the number of simultaneously supportable multiple-access users. In addition, a high-power amplifier (HPA) in a satellite transponder distorts the transmitted signal due to its nonlinearity and memory. The aim of this report is to study a satellite beam-forming (BF) method and to investigate its signal-to-interference-plus-noise ratio (SINR) degradation due to the KH and HPA nonlinearity effects. A closed form of an optimum BF vector is not available due to the HPA nonlinearity and memory, and a BF vector with simple complexity is desirable in practice. Therefore, this report proposes for a satellite transponder to use column vectors from a discrete Fourier transform matrix as precoding BF vectors for multiple ground terminals to meet their SINR demands. Each receiver can apply maximal ratio combining post processing for further processing gain, and should feedback his SINR observation to the transponder.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 14, 2018
- Accession Number
- AD1065942
Entities
People
- Hyuck M. Kwon
- Madhuprana Goswami
Organizations
- Wichita State University