Owing to the global bandwidth shortage in frequency bands below 6 GHz, higher frequency bands such as millimetre-wave bands will play integral roles in fifth-generation (5-G) communication systems. Beamforming is necessary for high-frequency bands to maintain system coverage and increase system capacity through spatial division multiple access. Moreover, more than one beam might be used simultaneously to enhance signal quality and prevent blockages. Recent studies have investigated, focussed on power loss characteristics in multi-beam operation, and compared the channel characteristics for single-beam operation. To provide robust channel characteristics, knowledge of the multipath characteristics in multi-beam operation is required in the design of 5-G communication systems. To fill this gap such as the multipath dispersion characteristics of outdoor-to-outdoor propagation in delay and angular domains, the present study analysed outdoor data measured at 38 GHz and presented the propagation losses (path losses and shadowing), root-mean-square delay spread, and angular spread in multi-beam operation. We believe that the dispersion statistics (delay and angular spreads) and propagation loss characteristics in multi-beam operation would be useful in the development of 5-G communication systems in high-frequency bands.
- multi-beam operation
- propagation characteristics