White Paper

White Paper: Guidelines to Low Cost Wireless System Design

Source: Nordic Semiconductor ASA

By Frank Karlsen
RF Designer, Wireless Communications
Nordic Semiconductor ASA

The recent availability of radio components operating in the license free Low Power Radio Device (LPRD) bands has made implementation of systems with wireless data transmission easier. Design of such systems was earlier a closely guarded secret, reserved for RF designers with years of experience.

Today, a multitude of vendors offer components ranging from simple single ON/OFF-keying transmitters to advanced multi-channel GMSK-transceivers.

Although the availability of off-the-shelf components has made wireless system design easier, the system designer still needs some fundamental knowledge of which radio-related parameters influence the overall system performance.

A key issue is transmission reliability; how will parameters such as sensitivity, output power, adjacent channel selectivity, operating frequency, etc. influence system performance? That is, the probability to transmit/receive an error free data package with the presence of other noise sources.

Reliable transmission range is also of utmost importance when designing a wireless system. Once output power and sensitivity is known, what other parameters are of importance? Environmental factors such as air humidity, range of sight, building materials, metal film sun-screened windows, etc. limit maximum useful range in addition to the choice of antenna implementation. The system designer must make his choice of the wireless solution mainly based upon the overall system environmental scene.

The large number of wireless component vendors has led to the need of caution when reading and interpreting datasheets. Some knowledge of "the not-so-fine art of creative RF-datasheet writing" may be in order. Why should you investigate closer if sensitivity is measured for a lower data-rate than the stated maximum? Is the effective data-rate stated for systems that require Manchester encoding? Checking just a few fundamental parameters may save time and frustration when realising that the circuit chosen does not comply with your system specifications.

The paper covers:

  • fundamental parameters and their definitions for integrated one-chip wireless components
  • system design guidelines based upon environmental factors, cost and reliability requirements
  • what to look for in RF-circuit data-sheet interpretation

Click here to download the complete paper in pdf format.