About TD-SCDMA Demodulation

89601B7NC adds TD-SCDMA (Time Division - Synchronous Code Domain Multiple Access) demodulation capability to your 89600 VSA software. The TD-SCDMA option provides modulation analysis for 3GPP N-TDD Time Division Duplex: A duplexing technique dividing a radio channel in time to allow downlink operation during part of the frame period and uplink operation in the remainder of the frame period. 1.28 Mcps Mega Chip Per Second: A measure of the number of bits (chips) per second in the spreading sequence of direct sequence spreading code. compliant signals (see TD-SCDMA Overview):

Demodulation Format	Specification
3GPP N-TDD	3GPP release 5 N-TDD 1.28Mcps 25102-560 UE User Equipment (e.g. cell phone) radio transmission and reception (TDD) 34122-500 UE conformance specification (TDD) 25105-560 BS Base Station - The equipment on the network side of a wireless communications link. The base station contains the tower, antennas and radio equipment needed to allow wireless communications devices to connect with the network. radio transmission and reception (TDD) 25142-570 BS conformance specification (TDD) 25221-550 Physical channels and mapping of transport channels (TDD) 25222-570 Multiplexing and channel coding (TDD) 25223-530 Spreading and modulation (TDD)

Demodulation Format

Specification

3GPP N-TDD

3GPP release 5 N-TDD 1.28Mcps 25102-560 UE User Equipment (e.g. cell phone) radio transmission and reception (TDD) 34122-500 UE conformance specification (TDD) 25105-560 BS Base Station - The equipment on the network side of a wireless communications link. The base station contains the tower, antennas and radio equipment needed to allow wireless communications devices to connect with the network. radio transmission and reception (TDD) 25142-570 BS conformance specification (TDD) 25221-550 Physical channels and mapping of transport channels (TDD) 25222-570 Multiplexing and channel coding (TDD) 25223-530 Spreading and modulation (TDD)

TD-SCDMA can descramble, despread, and demodulate TD-SCDMA modulated signals, for both uplink and downlink directions. The VSA's demodulator parameters are user-definable, providing the ability to customize the VSA to measure and analyze non-ideal signals. User-definable parameters include the chip rate, filter alpha, active slot threshold, downlink/uplink pilot codes, scramble codes, midamble base codes, and more (see TD-SCDMA Demod Properties).

The digital demodulator used in this VSA incorporates advanced technology that does not require coherent carrier signals or symbol-clock timing signals. The VSA has a built-in root raised-cosine filter, with user definable alpha (defines roll-off factor for chip shaping).

Along with typical digital demodulation trace data results, TD-SCDMA provides many unique Time Domain, Frequency Domain and Code Domain trace data results including the following:

Time data analysis includes CCDF, CDF, and PDF trace data for an individual timeslot and sub-frame.
Analysis Time and Analysis Spec trace data shows the time and frequency data for individual timeslots.
The Overall trace data shows time data for the entire sub-frame.

For an overview of all the available trace data results see About Trace Data.

There are also three numeric error summary tables, each providing various summary and error information for different segments of the TD-SCDMA signal:

The Overall Error Summary table provides chip timing error data, total power, data power and midamble power for each timeslot within the specified sub-frame.
The Composite Error Summary table provides error data for the composite signal for a specific timeslot and sub-frame.
The Channel Error Summary table provides error data for an individual code channel and layer for a specified timeslot and sub-frame.