Signal Processing

Impacts

High Sensitivity Radio Receiver

High Sensitivity Radio Receiver

Plextek has a history of producing effective solutions to radio problems. In this project, our client approached us with a need to offer a new solution to address recent technology changes in their marketplace. This required a high-sensitivity radio receiver capable of detecting and tracking signals from a variety of different sources, including 3G mobiles and base stations.

Conventional radio receivers are usually a compromise between sensitivity, latency and power-consumption. In this instance, the receiver was not required to demodulate the signal – it merely had to detect it in low-power conditions. Therefore, latency could be sacrificed for sensitivity.

Initial detection of a signal in low power conditions invariably requires the combination of both linear and non-linear detection techniques. The performance of the linear component determines the signal-to-noise ratio (SNR) of the detector’s discriminator input. The purpose of a discriminator is to decide when the input signal is something you are interested in. A non-linear component is then used to ‘tame’ the noise statistics and can either reduce the false alarm rate or allow the discriminator to use a lower threshold to increase sensitivity.

The performance of the linear component has the greatest effect on the sensitivity, but it is constrained by real world effects such as frequency errors, fading and etc. Therefore, the initial design allowed the balance between linear and non-linear components to be adjusted at runtime. It was built into an early prototype that the client was able to integrate with the rest of their system, enabling them to evaluate the performance and discuss results with key clients of their own.

This prototype leveraged COTS components with candidate algorithms being implemented in C. The prototype’s results were discussed with the client before agreeing to suitable design parameters, forming the basis of a number of further units that we designed and supplied.

The end result is a low size, weight and power handheld receiver that is low cost and easy to manufacture in high volumes. Our client requested that the receiver be powered by three AA alkaline batteries so that they could be easily replaced when the unit was deployed in the field. Key algorithms were also eventually implemented in a Field Programmable Gate Array (FPGA) because FPGAs present a very power efficient means of performing high speed complex signal processing tasks.

In this project, Plextek undertook the whole of the design work for this component of the client’s system. This included the power supply management, the Bluetooth interface to the rest of the client’s system, and the mechanical and thermal design. Throughout this process, we ensured that the result would be a product that could be manufactured efficiently and cheaply. Received positively by the client, the signal processing algorithms can detect and track a 3G signal more than 10 dB below a standard radio receiver’s sensitivity levels.

GPU Processing

GPU Processing

Contact Us – Email: hello@plextek.com or call: +44 (0) 1799 533 200

High Sensitivity Radio Receiver

High Sensitivity Radio Receiver

Plextek has a history of producing effective solutions to radio problems. In this project, our client approached us with a need to offer a new solution to address recent technology changes in their marketplace. This required a high-sensitivity radio receiver capable of detecting and tracking signals from a variety of different sources, including 3G mobiles and base stations.

Conventional radio receivers are usually a compromise between sensitivity, latency and power-consumption. In this instance, the receiver was not required to demodulate the signal – it merely had to detect it in low-power conditions. Therefore, latency could be sacrificed for sensitivity.

Initial detection of a signal in low power conditions invariably requires the combination of both linear and non-linear detection techniques. The performance of the linear component determines the signal-to-noise ratio (SNR) of the detector’s discriminator input. The purpose of a discriminator is to decide when the input signal is something you are interested in. A non-linear component is then used to ‘tame’ the noise statistics and can either reduce the false alarm rate or allow the discriminator to use a lower threshold to increase sensitivity.

The performance of the linear component has the greatest effect on the sensitivity, but it is constrained by real world effects such as frequency errors, fading and etc. Therefore, the initial design allowed the balance between linear and non-linear components to be adjusted at runtime. It was built into an early prototype that the client was able to integrate with the rest of their system, enabling them to evaluate the performance and discuss results with key clients of their own.

This prototype leveraged COTS components with candidate algorithms being implemented in C. The prototype’s results were discussed with the client before agreeing to suitable design parameters, forming the basis of a number of further units that we designed and supplied.

The end result is a low size, weight and power handheld receiver that is low cost and easy to manufacture in high volumes. Our client requested that the receiver be powered by three AA alkaline batteries so that they could be easily replaced when the unit was deployed in the field. Key algorithms were also eventually implemented in a Field Programmable Gate Array (FPGA) because FPGAs present a very power efficient means of performing high speed complex signal processing tasks.

In this project, Plextek undertook the whole of the design work for this component of the client’s system. This included the power supply management, the Bluetooth interface to the rest of the client’s system, and the mechanical and thermal design. Throughout this process, we ensured that the result would be a product that could be manufactured efficiently and cheaply. Received positively by the client, the signal processing algorithms can detect and track a 3G signal more than 10 dB below a standard radio receiver’s sensitivity levels.

GPU Processing

GPU Processing

Contact Us – Email: hello@plextek.com or call: +44 (0) 1799 533 200

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