Transmitting 2 PCM Data Streams in S-band: Combining 10kHz and 250kHz on a Single Carrier

Transmitting two Pulse Code Modulation (PCM) data streams on a single carrier in the S-band frequency range is a complex task that requires a deep understanding of signal processing and telecommunications. The S-band, which ranges from 2 to 4 GHz, is commonly used for radar, communications, and space-related applications. The challenge here is to transmit two different data streams, one at 10kHz and the other at 250kHz, using a single carrier. This article will delve into the intricacies of this process, providing a comprehensive guide on how to achieve this with a Phase Modulation (PM) transmitter, a dish antenna, and two S-band telemetry receiving chains.

Understanding PCM and S-band

Pulse Code Modulation (PCM) is a method used to digitally represent analog signals. In the context of this discussion, the two PCM data streams are at different frequencies – 10kHz and 250kHz. The S-band is part of the microwave band of the electromagnetic spectrum, and it is used for various applications, including communication with satellites and radar systems.

Combining Two PCM Data Streams

To transmit two PCM data streams on a single carrier, you need to combine the two streams into one. This can be achieved using a process called multiplexing. There are different types of multiplexing techniques, but for this scenario, Frequency Division Multiplexing (FDM) would be the most suitable. FDM works by assigning a unique frequency range to each data stream. In this case, the 10kHz and 250kHz data streams would each be assigned their own distinct frequency range within the S-band.

Transmitting the Combined Data Stream

Once the two data streams have been combined into a single stream using FDM, the next step is to transmit this combined stream. This is where the PM transmitter and the dish antenna come into play. The PM transmitter will modulate the combined data stream onto a carrier wave in the S-band, and the dish antenna will transmit this modulated signal.

Receiving the Transmitted Signal

The transmitted signal can be received using the two S-band telemetry receiving chains. Each receiving chain will be tuned to the frequency range assigned to one of the data streams during the multiplexing process. This will allow each receiving chain to demodulate and decode its respective data stream.


Transmitting two PCM data streams on a single carrier in the S-band involves a series of steps, including multiplexing the data streams, modulating the combined stream onto a carrier wave, and transmitting the modulated signal. The receiving chains then demodulate and decode the received signal to retrieve the original data streams. While this process may seem complex, with a solid understanding of signal processing and telecommunications, it is entirely feasible.