Systems and Protocol IP
GBT's Systems IP pertains to technologies essential to the 3G W-CDMA wireless systems and are incorporated into the official W-CDMA standards. GBT has issued and pending patents in the following areas:
Random Access Channel
In a CDMA system with a Base Station (BS) and a plurality of Mobile Stations (MS), the BS transmits a synchronization signal over a broadcast synchronization channel. The MS determines System Frame Timing information from the received synchronization channel. The MS transmits a plurality of segments (preambles) at sequentially increasing power levels. The BS receives a preamble at a detectable power level. The BS responds to the MS with an acknowledgment signal. Upon receipt of the acknowledgment signal, the MS starts transmitting data and or control information.
Header in a Multi-Code Transmission
A stream of data is de-multiplexed to a set of lower rate parallel data streams. Each parallel data stream is spread by a chip sequence, which is orthogonal to the chip sequence signals used for the other parallel data streams. The parallel data streams are then algebraically combined to a multi-channel spread spectrum signal. A header device concatenates headers to the multi-channel spread spectrum signal. At the receiver, matched filters are used to detect the orthogonal chip sequence signals and the header signals. A processor coupled to the header detection means (header matched filter), generates control and timing signals. Receiver spread spectrum means for despreading the multi-channel spread spectrum signal into a set of received spread spectrum channels.
Common Packet Channel
GBT's most significant Protocol IP is a group of patents relating to the Common Packet Channel ("CPCH") Radio Access Protocol IP. CPCH is now the only packet access protocol of the 3G W-CDMA standard that is optimized for medium sized packet length, which is the most common length for email and web browsing transactions. GBT is the pioneer of CPCH and has worked with 3G standard bodies in the United States and around the world to incorporate this once-unfeasible packet data communication feature into 3G systems.
Implementation IP
GBT's Implementation IP portfolio pertains to its Programmable Matched Filter (PMF) based technology. The PMF based technology is a key breakthrough for the realization of high data rate delivery because its signal acquisition is 5 - 10 times faster than comparable technologies and has lower power requirements than any other solution available. These are significant benefits relative to the cost of both terminals and related systems equipment. Most importantly, the benefits of the PMF based technologies extend beyond the W-CDMA systems.
