At the beginning of radio, few people would have guessed that we would be wondering now about the difference between the narrow band and wideband meter used in radio communications. At that time, someone guessed that using the small frequency deviation could produce a narrow spectrum, narrower than the AM, because that spectrum could be restricted to a larger range of frequencies. Systems are defined as wideband or narrowband depending on the transmission bandwidth.
1. Rate Transmissions
A narrowband system supports a lower rate transmission, while the wideband system supports a higher rate transmission. The bandwidth channel is assessed and associated with the coherence bandwidth, which is the frequency band where all components can be affected equally.
2. Bandwidth KHz
The narrow band system is an SSB (Single Side Band) communication grade system, occupying 2 KHz of bandwidth, while the wide band is an AM music broadcast system, occupying 20 KHz of bandwidth – and sometimes even more.
3. Difference in Connection Type
A narrow band system uses a point to point connection because the broadcast aims at numerous receivers within a specific region. Serving many people at the same time, the point connection allows a larger bandwidth. On the other hand, the wide band system uses a broadcasting station that runs on regular schedules for operating times, whereas the point to point communication station can operate only when needed. The narrow band system ensures more stable and longer connections, while the wide band can suffer from frequency instabilities.
4. Signal Types
The narrow band system can achieve communication modulating sinusoidal carriers that carry and transmit the information. The signal used is defined by this sinusoidal nature, occupying a narrow band in the frequencies domains. The wide band application and system can use any waveform and signal type able to satisfy the definition of the wide band. Deciding on the use of a particular waveform depends on the application and design requirements.
5. Coding System
All coding channels and sources applicable for a narrow band system can be used in a wide band system as well. The main difference here is that the wide band system uses a coding signal that is easier to deal with because the signal is already in a digital form. The wide band system uses a type of coding technology that could be considered as the laver of the communication systems. The wide band system also uses a coding system called pseudo random noise coding, which is used for channelization. The greater advantage of this system is that it helps to avoid jamming.
The narrow band system modulation includes AM (amplitude modulation) and FM (frequency modulation), PM ( phase modulation) and more. The wide band system uses analog or digital modulation, and pulse position modulation, which permits the use of optimal receiving filters.
The main disadvantage of the narrow band system is that it is not appropriate for high speed communications due to the narrow receiver bandwidth. In general, the speed is limited to less than 9,600bps. The wide band system can reach much higher speeds than 10,000bps.