Increased data rates for communication systems with adaptive antennas
Abstract
This paper describes a digital communication system using spread spectrum and an adaptive array, where the signal bandwidth is proportional to the data rate only. The system is compared to a previous system, in which a biphase modulated spread spectrum signal was used. In the previous system, the signal bandwidth for a given data rate was increased by the spectrum spreading ratio. In this paper, the combining of the biphase signal with an orthogonal biphase signal (with the same bandwidth) modulated by data only is considered. The resulting four-phase signal has a bandwidth determined only by the data rate and not by the spreading ratio. This paper describes the communication system using the four-phase signal and discusses the tradeoffs involved in the system design. Experimental and theoretical results show that the four-phase system has the same interference nulling capability as the biphase system, with a several times higher data rate for the same signal bandwidth.
- Publication:
-
ICC 1982 - The Digital Revolution, Volume 2
- Pub Date:
- 1982
- Bibcode:
- 1982icc.....2....4W
- Keywords:
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- Adaptive Control;
- Antenna Arrays;
- Pulse Communication;
- Spread Spectrum Transmission;
- Bandwidth;
- Bit Error Rate;
- Demodulation;
- Phase Shift;
- Communications and Radar