A multi-carrier base station receiver using a delta-sigma oversampling A/D converter

This paper presents the results of work at TRW in developing a multi-carrier receiver for cellular base station applications. Replacing existing single carrier receivers with a multi-carrier receiver has the potential to significantly increase the capacity of existing mobile phone networks and reduce the cost per carrier. Implementation of a multi-carrier receiver has been limited by the large dynamic range requirements for GSM/EDGE and WCDMA standards, with the GSM 900 MHz band presenting the greatest challenge. TRW is leveraging several proprietary technologies that enable and facilitate this development, including the latest product in a series of high performance analog-to-digital converters (ADCs). The stressing requirements for very high dynamic range (up to 108 dB SNR), wide bandwidth, and high linearity are met by employing a delta-sigma ADC that redefines the state-of-the-art. TRW's world-class InP process is used to fabricate devices capable of the high level of oversampling needed to satisfy the demanding performance values. We describe the receiver architecture and present preliminary test results from our first engineering model, demonstrating the practicality of a multi-carrier receiver for cellular base stations.