Glossary

Personal Communication Services (PCS) Emerging wireless networks using digital modulation formats and operating in the frequency band between 1.8 and 2.4 GHz.

Pilot Channel An unmodulated, direct- sequence, spread-spectrum signal transmitted continuously by each CDMA base station. The Pilot channel allows a mobile station to acquire the timing of the forward CDMA channel, provides a phase reference for coherent demodulation, and provides a means for signal strength comparisons between base stations for determining when to hand off.

Pilot PN Sequence A pair of modified maximal length PN sequences with period 215 used to spread the forward CDMA channel and the reverse CDMA channel. Different base stations are identified by different pilot PN sequence offsets.

Pilot PN Sequence Offset Index The PN offset in units of 64 PN chips of a pilot, relative to the zero offset pilot PN sequence.

PN Chip The time duration of one binary bit in the PN sequence, which is equal to the reciprocal of the frequency at which the PN sequence generator operates. For example, if the PN generator operates at 1.2288 MHz, then a PN chip is 813.802 ns.

PN Sequence Literally "pseudo-noise sequence." A periodic binary sequence (with 0 mapped to 1, and 1 mapped

to −1). Typically a PN sequence has good autocorrelation which (when normalized) equals 1 for zero shift between the two sequences, and −1/N, where N is the period, for all other shifts.

PN Sync Pulse A signal to the CDMA Generator that initiates pilot PN sequence generation. The start of each pilot PN sequence is synchronized at the Test Set’s RF IN/OUT port to the 27 millisecond frame clock.

Quadrature Phase Shift Keying (QPSK) A form of modulation that applies different data sequences to two carriers separated by 90 ° .

Quadrature Spreading Frequency spreading performed using pilot PN sequences at a 1.2288 Mcps rate. Also referred to as "short sequence spreading".

Reference Signal A replica of the ideal CDMA waveform. The reference signal resides on the Cellular Adapter’s DSP analyzer and is correlated with a signal- under-test to determine waveform accuracy and timing offset.

Reverse CDMA Channel The CDMA channel from the mobile station to the base station. From the base station’s perspective, the reverse CDMA channel is the sum of all mobile station transmissions on a CDMA frequency assignment.

Reverse Link The link direction from the mobile station to the base station. Also referred to as the uplink.

Reverse Traffic Channel A reverse CDMA channel used to transport primary traffic, secondary traffic, and signaling traffic from a single mobile station to one or more base stations.

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