User's Manual

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The pilot beacon generator facilitates E911 and other location based services (LBS) for in building and/or DAS based installations
of CDMA2000/1xEV-DO cellular networks. In these situations the normal methods based for location determination, direct
reception of GPS by the mobile station or triangulation using the signals from multiple base stations, do not work. Signals from
the GPS system are suf• ciently weak that even if the mobile station’s GPS receiver might ultimately be able to lock on to the
satellites, the acquisition time will be too long. And since indoor service is typically provided either by a single strong local cell
or by using a repeater, there aren’t multiple signals on which to triangulate while DAS based deployments result in too many
signals with indeterminate timing. By placing a pilot signal at a known PN offset the LBS algorithm can quickly and reliably be
made aware that it is within a speci• c building or other location where normal location determining solutions are ineffective. This
information can be used to aid the GPS receiver in acquiring signals if they are
present or be used as a position report directly
until more accurate information becomes available.
3GPP2 The standards body comprised of representatives of interested companies that is responsible for the
development and maintenance of the operational standards for the CDMA2000 system. Http://www.3gpp2.
org
AGC Automatic Gain Control
CDMA Code Division (or, Domain) Multiple Access: The general term for the technology used in the CDMA2000
system as well as others. Also a shorthand reference to the CDMA2000 system and its derivatives such as
1xEV-DO
Chip A single element, a ‘1’ or a ‘0’, of the PN Sequence in a CDMA system. The chip rate for the CDMA2000
system is 1.2288 Mchips/second.
CSI Cellular Specialties Incorporated
DAS Distributed Antenna System
ERP Effective Radiated Power
EST Even Second Tick: In the CDMA2000 cellular system all time values are referenced to the start of the even
seconds of time as indicated by GPS.
FCC Federal Communications Commission
FPGA Field Programmable Gate Array
GPS Global Positioning System
IF Intermediate Frequency
LED Light Emitting Diode
NEMA National Electrical Manufacturers Association
PA Power Ampli• er
PN Pseudo random Number: A number chosen by some algorithm that approximates a random process. Can
be short for “PN Sequence”, “PN Number”, or “PN Offset” when discussing the CDMA2000 system.
PN Number In the CDMA2000 system only a subset of the possible PN Offsets are used for base station identi• cation.
Each of these allowed offsets is given a unique number from 0 to 511.
PN Offset In the CDMA2000 System each base station is identi• ed by the offset in time from the EST at which the
start of the Pilot PN Sequence occurs. The offset is speci• ed in terms of number of chips.
PN Sequence A sequence of pseudo random numbers. In the CDMA2000 system several such sequences are used. The
one relevant to ICEBreaker is the Pilot, or Short, sequence which is a 2
15
element long sequence of ones
and zeros.
PPS Pulse per Second: Refers the pulse repetition rate of the timing signal used as a time reference.
RF Radio Frequency
SBC Single Board Computer
Tau Timing Offset or Delay Adjustment: In the CDMA2000 system the timing of the downlink signal is required
to be aligned with the EST as it is transmitted from the antenna. Tau allows the timing of the internal PN
Sequence to be adjusted to compensate for the delays of the base station hardware such that the timing
will be correct at the antenna
USB Universal Serial Bus
Acronyms and De• nitions
Product Introduction