CWave’s unique implementation of ultra-wideband delivers unparalleled data rates over coaxial cable networks
Invention usually occurs when problems are approached from a fresh perspective. Pulse~LINK’s CWave technology borrows from Ultra-Wideband (UWB) communications, combining unconventional RF techniques with known modulation and Forward Error Correction (FEC) schemes.
Pulse~LINK’s imagination didn’t end with CWave’s design. New applications, unique in UWB communications, sprang from the same lateral thinking. Once considered a wireless-only technology, Pulse~LINK was the first company to describe the use of UWB over wired media. Specifically, when used over shielded media, such as coaxial cable, CWave UWB is able to operate at higher power levels and utilize frequencies outside the FCC’s UWB spectrum mask.
CWave’s magic happens when a 4 GHz carrier is mixed with a 1.3 GHz signaling rate. This combination produces a waveform occupying frequency from 2.7 GHz to 5.3 GHz (with additional harmonics). All sideband emissions are filtered, leaving a 1.3 GHz-wide signal with a center frequency around 4 GHz.
CWave’s raw data rate is a multiple of the modulation and signaling rate. The simplest form of modulation uses Binary Phase Shift Keying (BPSK). BPSK yields 1 bit per hertz or (1 bit x 1.3 GHz = 1.3 Gbps). 8PSK delivers 3 bits per Hertz or 4 Gbps, etc. In addition, the effective bandwidth of each digital modulation mode can be doubled or tripled by adding a second or third additional frequency band. For example, a 4 GHz center frequency band can be combined with a 2.7 GHz center frequency band to deliver a raw data rate of 8 Gbps using 8PSK.
The following table shows raw data rates using various modulation techniques together with multiple bands.
| Modulation | Bits / Hz | 1 band (Gbps) | 2 band (Gbps) | 3 band (Gbps) |
| BPSK | 1 | 1.35 | 2.7 | 4.05 |
| QPSK | 2 | 2.7 | 5.4 | 8.1 |
| 8PSK | 3 | 4.0 | 8 | 12 |
Currently in its first generation, CWave supports BPSK modulation and single band operation (per chipset). Gen-1 products are capable of 1.3 Gbps raw throughput with a center frequency of 4 GHz. Bandwidth can be doubled by using a second chipset operating at a 2.7 GHz center frequency. Gen-2 silicon, now under development, will support 8PSK modulation and dual-band operation, delivering 8 Gbps raw throughput from a single chipset. Pulse~LINK expects to ship Gen-2 silicon in Q2/Q3, 2015.
With CWave’s Gen-2 silicon, Gigabit Ethernet is the new bottleneck.