This paper demonstrates a new channel-selective multi-cell processing predistortion technique that compensates for the nonlinearities of multi-carrier transmitters. The proposed technique uses independent processing cells to compensate for the intra-band and inter-band distortions of nonlinear transmitters. This frequency-selective feature of the proposed technique significantly reduces the minimum sampling rate requirements of analog-to-digital and digital-to-analog converters, which are a critical issue for conventional digital predistortion (DPD) techniques dealing with wideband signals. The proposed technique was evaluated with four-carrier (1001) and six-carrier (100001) WCDMA signals, using a nonlinear 10-Watt power amplifier. The performance of the proposed technique was compared with look-up table, multi-branch and recently proposed frequency-selective DPDs, in terms of adjacent-channel power ratios (ACPRs) and sampling rate requirements. The proposed technique improved the ACPR and the carrier-to-intermodulation power ratio (CIMPR) of the 1001 WCDMA signal by more than 13 dB and 10 dB, respectively.

A design technique to realise a low-complexity multiple-input multiple-output (MIMO) receiver using a time-multiplexed single front-end receiver is introduced. The architecture uses a simple front-end receiver where it delivers radio frequency signals to baseband section. The theory behind this architecture is analysed and the diversity gain of the proposed receiver is investigated. This simple MIMO receiver can provide the same diversity gain as the diversity gain of the multiple front-end. Moreover, the experimental studies are conducted to evaluate the diversity gain of the proposed architecture. Excellent agreement between the simulated and measurement results is obtained. The proposed architecture provides a new receiver design technique with lower complexity, power consumption and cost in MIMO systems.

This paper investigates the employment of antenna subset selection in differential space-time block codes (STBC) over Rayleigh and Rician slow fading channels. We assume the transmission of orthogonal space-time block codes specifically Alamouti codes. Our proposed antenna subset selection chooses the antenna set that maximizes the channel Frobenius norm. The simulation results show that the proposed method improves the system performance. The simulation results show that our proposed selection algorithm leads to diversity and power gains.