Эффективность линейной обработки сигналов в системах связи в условиях многолучевого ионосферного канала декаметрового диапазона

The architecture of digital High Frequency (HF) data modem is considered. Link level simulation of HF wireless communication system with bandwidth of 3 kHz was carried out for the multipath ionospheric channel model. The main link level performance metrics such as BER, PER and system throughput are provided and analyzed. It is shown that in frequency-selective two ray channel, the linear MMSE equalization at the receiver provides efficient ISI elimination for all modulation and coding schemes except high-order modulations that are required development of non-linear quasi-optimal signal processing algorithms.Рассмотрены системы связи декаметрового диапазона, работающие в условиях многолучевого ионосферного пространственного канала. С помощью имитационного моделирования на физическом уровне исследованы основные характеристики системы (вероятность битовой и блоковой ошибки, пропускная способность). Показано, что в условиях частотно-селективного канала в полосе 3 кГц линейный алгоритм эквализации обеспечивает высокую эффективность подавления межсимвольной помехи для всех скоростей передачи данных, кроме самой высокой

Application of MIMO technology in wideband millimeter range wireless communications systems

A concept of using MIMO technology in millimeter range wireless communications systems with orthogonal frequency division multiplexing is considered. The concept is based on dividing transmitting and receiving multi-element antenna arrays into separate sub-arrays with analogue radiation pattern shaping and on using two most powerful space sub-channels for information transmission. Sequence and structure of transmitted packets between transceivers are suggested that allow for obtaining information on communications channel based on additional training sequences without feedback channel. Modeling results of communications system’s operation in conditions of multipath frequency-selective fading channel are presented

The Efficiency of Linear Signal Processing in High Frequency Communication Systems for Multipath Ionospheric Propagation Environment

The architecture of digital High Frequency (HF) data modem is considered. Link level simulation of HF wireless communication system with bandwidth of 3 kHz was carried out for the multipath ionospheric channel model. The main link level performance metrics such as BER, PER and system throughput are provided and analyzed. It is shown that in frequency-selective two ray channel, the linear MMSE equalization at the receiver provides efficient ISI elimination for all modulation and coding schemes except high-order modulations that are required development of non-linear quasi-optimal signal processing algorithms