# Code division multiple access Channel access method where several transmitters send information over the same channel. Allows for [uplink](uplink.md) power control - faster compared to [GSM](Global%20System%20for%20Mobile.md) (800 times per second) - reduces intra-cell interference - reduces power consumption by measuring the channel quality and adjusting transmit power accordingly - maintains a constant [data rate](data%20rate.md)  ## Advantages - Many users share the same frequency concurrently - Channels are released if not occupied by a user - Soft [handoff](Handoff.md) (make-before-break) can exploit spatial [diversity](diversity%20scheme.md) ## Disadvantages - [Near-far problem](Near-far%20problem.md) - [cell breathing](Cell%20breathing.md) - Transmitting a wideband signal makes things complicated - Frequency selectivity [channels](../RF%20Chip%20Design/channels.md) - Need to perform one signal processing - [Rake receiver](Rake%20receiver.md) needed to improve reception - [Self-jamming](Self-jamming.md) # References 1. https://en.wikipedia.org/wiki/Code-division_multiple_access 2. [TELE4652-lecture-00](../../03%20-%20University/TELE4652/Lectures/TELE4652-lecture-01.pdf)