Method and apparatus for a spectrally compliant cellular communication system
View Patent ↗A system for wireless data transmission that uses a channel bandwidth, channel separation, and radio frequency power spectrum which is compatible with existing deployments of wireless voice services. The transmitted waveforms are thus compatible with existing cellular networks. However, the time domain digital coding, modulation, and power control schemes are optimized for data transmission. Existing cellular network sites can thus be used to provide a high speed service optimized for wireless data traffic without the need for new radio frequency planning, and without interfering with existing voice service deployments.
1. A method for use in a subscriber unit for providing data transmissions to a base station in a wireless communication network, the method comprising:
receiving a plurality of allocated channels from the base station, wherein at least one of the plurality of allocated channels is used for data transmissions;
encoding a data signal using a data encoding scheme optimized for data transmissions, wherein the data encoding scheme uses an encoding different than the encoding used for a voice signal, wherein a number of the plurality of allocated channels changes during the transmission of the data signal; and
modulating the encoded data signal such that the modulated bandwidth and power spectrum of the encoded data signal are optimized for data transmissions, wherein the modulated bandwidth and power spectrum of the encoded data signal is the same as the modulated bandwidth and power spectrum for a modulated voice signal; and
transmitting the modulated data signal;
wherein the plurality of allocated channels are allocated on an instantaneous basis, and
wherein the plurality of allocated channels are allocated based on the demands of the data transmissions.
2. The method of claim 1 wherein the modulating uses spread spectrum modulation to produce a code division multiple access (CDMA) signal.
3. The method of claim 1 wherein the rate of the encoding is based on signal strength.
4. The method of claim 1 wherein the rate of encoding is based on a signal to noise ratio.
5. The method of claim 1 wherein the rate of encoding is based on a signal to interference ratio.
6. The method of claim 1 further comprising:
transmitting the modulated data signal over one or more channels, such that it is compatible with existing cellular networks from a frequency domain perspective.
7. A code division multiple access (CDMA) user device comprising:
an antenna configured to receive a plurality of allocated channels from a base station, wherein at least one of the plurality of allocated channels is used for data transmissions;
an encoder configured to encode a data signal using a data encoding scheme optimized for data transmissions, wherein the data encoding scheme uses an encoding different than the encoding used for a voice signal, wherein a number of the plurality of allocated channels changes during the transmission of the data signal; and
a modulator configured to modulate the encoded data signal such that the modulated bandwidth and power spectrum of the encoded data signal are optimized for data transmission, wherein the modulated bandwidth and power spectrum of the encoded data signal is the same as the modulated bandwidth and power spectrum of a modulated voice signal,
wherein the plurality of allocated channels are allocated on an instantaneous basis, and
wherein the plurality of allocated channels are allocated based on the demands of the data transmissions.
8. The CDMA user device according to claim 7 wherein the modulator is configured to use spread spectrum modulation to produce a code division multiple access (CDMA) signal.
9. The CDMA user device according to claim 7 wherein the modulator is configured to modulate the encoded data signal at a rate based on signal strength.
10. The CDMA user device according to claim 7 wherein the modulator is configured to modulate the encoded data signal based on a signal to noise ratio.
11. The CDMA user device according to claim 7 wherein the modulator is configured to modulate the encoded data signal based on a signal to interference ratio.