GPS Applications in Consumer Electronics


After describing the basic theories of GPS, let's move on to subject matter; i.e. to investigate the technical difficulties that GPS faces in consumer electronics and their solutions. First of all, consumer electronics in this article refer to portable or handheld devices, including PDAs, handheld PCs (palm PCs) and, smart phones and NAVI systems.

GPS was customarily applied to the tracking and navigation of small aircrafts, yachts and boats and people. After it is added to portable and handheld devices, GPS IC designers discovered that there are 4 barriers to overcome. First, as well as the critical problem, is the receiving sensitivity of GPS on portable and handheld devices. While these devices are often used in urban areas and inside buildings which are considered as the natural killer of GPS, signals will be weakened and multi-path effect will occur. Sometimes, signals cannot be received in an indoor environment. Therefore, Trimble has been making continual efforts to enhance the performance of the RF IC in order to optimize the receiving sensitivity of its GPS products.

Power consumption is the second problem to overcome because power-saving has always been a central problem of all portable and handheld devices. Currently, the power consumption of GPS IC from most suppliers is around 200mW to 400mW. In addition to further reducing the basic power consumption of GPS ICs, effective power management is one of the important tasks in IC design. The M-Loc design of Trimble is one of the best in this area. The power consumption can be maintained at under 100mW with effective program control.

The size of GPS receiver is the third problem. In general, components in a GPS receiver include an emission IC, a GPS ASIC processor, a CPU and memory. Together with other circuits, the size of an entire GPS IC is as big as a business card. Yet, it is still too big for portable and handheld devices. Therefore, Trimble develops the M-Loc GPS module of a smaller size. Furthermore, the module shares the memory that is installed on the portable and handheld devices in order to reduce the size of the module extensively.

Price is the fourth problem. A product must be competitive in terms of price in order to become popular. This suggests that GPS suppliers must enter the portable or handheld device market (cellular phones, PDAs etc) in order to balance the cost with high sales. GPS suppliers that can overcome these 4 barriers will be able to enter the consumer electronics market successfully.