Wideband flexible microwave radio-steps towards the software radio

The paper discusses the design and development of a microwave radio transceiver at 1.4 GHz, which implements multirate signal processing algorithms to provide variable channel bandwidths, symbol rates on the channel, two constellation PSK modulation schemes, and wide frequency tuning range using fractional-N synthesis to achieve fine frequency resolution and low noise. To avoid RF switching, there is no analogue channel filtering, where all adjacent and some spurious blocking is achieved in the digital baseband circuits. The requirements on receiver and transmitter linearity, filtering requirements, ADC/DAC performance are discussed and analysed, and conclusions applied to future third generation and possible dual-mode software mobile radios. The paper focuses on the practical implementation of software radio techniques and practical results are discussed