Narrowband vs. Broadband Channels

Cadence System Analysis

Key Takeaways

Bandwidth represents the range of frequencies used in communication.
Based on the size of the frequency band, there are two classifications: narrowband and broadband.
Narrowband signals cover only a small fraction of the frequency spectrum, whereas broadband signals occupy a fairly large portion.

In the communication industry, we often discuss frequency and bandwidth, as they are closely related to the performance of the system. For example, uplink and downlink frequencies and their bandwidth are crucial in satellite communications. With greater bandwidth, the throughput, spectrum efficiency, performance, etc. of the satellite communication system increases.

Bandwidth represents the range of frequencies used in communication. If you are operating a data transmission in the L band, which is of frequency 1-2 GHz, then the bandwidth is 1 GHz. The higher the bandwidth, the higher the data transfer rate of the communication system.

Based on the size of the frequency band, there are two classifications of bandwidth: narrowband and broadband. Let’s look at these two bandwidths and differentiate between them.

Narrowband vs. Broadband

Narrowband	Broadband
The frequency range where the gain remains constant	The frequency response is not flat like that in narrowband communication
Narrow bandwidth or narrow frequency range	Broader bandwidth or frequency range
The band should be lower than the coherence bandwidth	Broadband exceeds coherence bandwidth
Suitable for low-power, reliable, short-range communication	Ideal for communication systems requiring higher data transfer rates and long-range
Transmit power is high	Transmit power is less

Example Time: Narrowband vs. Broadband for Internet Connectivity

Dial-up and digital subscriber line internet connectivity are examples of narrowband and broadband applications, respectively. The following table compares the two in the context of narrowband vs. broadband communication.

Dial-Up Internet Connection	Digital Subscriber Line (DSL) Internet Connection
Narrowband internet connectivity	Broadband internet connectivity
Established in the computer using a modern attached to the telephone lines	DSL uses telephone lines but uses higher frequencies that allow faster data transmission through the same telephone lines
Low data speed (less than 56kps)	Higher data speed (minimum speed of 10-20 Mbps)
Experiences lag when downloading large files	Minimal lag when downloading large files, seamless gaming, and HD video streaming possible
Internet is available only when the phone is not in use	Internet is available even when the phone is in use (splitting frequencies to multiple channels)
Comparatively high network congestion	Minimal network congestion

Parametric Comparison

Parameter	Narrowband	Broadband
Transmit power efficiency	High	Low
Frequency accuracy	Good	Even better than narrowband
Noise and interference	Affects the signals	Low noise and not an issue
Infrastructure	Good, as the narrowband is used for short-range communication	Infrastructure to be established widely
Bandwidth efficiency	Very high	Low
Range	Short	Long
Data transfer rate	Low	High
Coverage	Narrow coverage	Wide coverage
Security	Highly secured	Highly secured
Environmental penetration	High penetration	Low penetration

Narrowband Channels vs. Broadband Channels

Spectrum: Narrowband signals cover only a small fraction of the frequency spectrum, whereas broadband signals occupy a fairly large portion.

Signal power: In narrowband channels, the transmit signal power required is low due to the vectorial addition of the paths. Broadband signals are subject to the algebraic addition of these paths and demand higher signal power.

Complexity: Narrowband channels are less complex compared to broadband channels.

Location: As the operation power requirements are less, narrowband systems are suitable for a fixed location and shorter-range applications, whereas broadband channels are used for long-range applications.

Amount of data: Narrowband channels have limitations in data, voice, and video transfer, whereas broadband channels carry huge amounts of data.

Mobile application: Narrowband receiver capability is impacted by the movement of the transmitter or receiver. In broadband communications, the mobility of the transmitter or receiver does not affect channel communications.

Channel noise: In narrowband channels, effective filtering is used to mitigate interferences outside the bandwidth as well as noise. Broadband channels limit the noise and interference outside the bandwidth using complex filters.

Signal-to-noise ratio: Narrowband channels do not require many filters compared to broadband channels to achieve a good signal-to-noise (SNR) ratio and signal-to-interference ratio.

Channel-to-channel interference: As the transmitted energy is concentrated to a narrow portion of the frequency spectrum, good channel-to-channel isolation is present in narrowband communication (more so than broadband).

Narrowband channels pass spectral components with the same gain or phase. This results in flat fading in the channel. Narrowband channels are also known as flat fading channels due to uniform fading. Even if more frequencies are added to narrowband channels, the uniform fading continues and no benefit is gained from the modification. Comparing narrowband vs. broadband channels, the latter is capable of selective fading and fading of different frequencies impacting different channels.

Developing Narrowband and Broadband Systems With Cadence Tools

Cadence’s suite of design and analysis tools can help you in the design and development of narrowband and broadband systems with high SNR, high efficiency, and excellent performance. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.

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