Rach ramp-up acknowledgement

An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a first base station (BS), a second base station, and a plurality of remote stations (RS) with each remote station having an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver, the improvement comprising:

• a first BS-spread-spectrum transmitter located at said first base station, for transmitting a first broadcast common-synchronization channel having a first common chip-sequence signal common to the plurality of remote stations, the first broadcast common-synchronization channel having a first frame-timing signal;
• a second BS-spread-spectrum transmitter located at said second base station, for transmitting a second broadcast common-synchronization channel having a second common chip-sequence signal common to the plurality of remote stations, the second broadcast common-synchronization channel having a second frame-timing signal;
• a first RS-spread-spectrum receiver, located at a first remote station of the plurality of remote stations, for receiving the first broadcast common-synchronization channel, and determining first frame timing at said first RS-spread-spectrum receiver from the first frame-timing signal;
• said first RS-spread-spectrum receiver for receiving the second broadcast common-synchronization channel, and determining a second frame timing at said first RS-spread-spectrum receiver from the second frame-timing signal;
• means, based on any of power levels and probabilities of error, located at said first RS-spread-spectrum receiver, for determining from the first broadcast common-synchronization channel and from the second broadcast common-synchronization channel, to transmit to said first base station;
• a first RS-spread-spectrum transmitter, located at said first remote station of said plurality of remote stations, for transmitting a first access-burst signal;
• said first BS-spread-spectrum receiver for receiving the access-burst signal at a detected-power level;
• said first BS-spread-spectrum transmitter for transmitting to said first RS-spread-spectrum receiver, responsive to receiving the first access-burst signal, a first acknowledgment signal;
• said first RS-spread-spectrum receiver for receiving the first acknowledgment signal;
• and
• said first RS-spread-spectrum transmitter, responsive to the first acknowledgment signal, for transmitting to said first BS-spread-spectrum receiver, a first spread-spectrum signal having data.

A base-band processor, for use in a code-division-multiple-access (CDMA) wireless base station having a modulator and a demodulator, the base-band processor comprising:

• a preamble processor, coupled to the demodulator, for detecting a preamble in a received spread-spectrum signal;
• a data processor, coupled to the demodulator, for detecting and processing any data contained in the received spread-spectrum signal;
• an encoder, for encoding data;
• an interleaver, coupled to the encoder, for interleaving encoded data;
• packet a packet formatter, coupled to the interleaver, for formatting the interleaved data into a packet;
• and
• a controller coupled to the preamble processor and coupled for controlling the modulator, the data processor and the packet formatter, such that in operation the base-band processor is for performing the following steps:
• detecting a first one of a sequence of coded preamble signals embedded in a first spread-spectrum signal received at an adequate power level;
• upon detection of the first coded preamble signal at the adequate power level, generating a packet comprising an acknowledgement signal, and outputting the packet comprising the acknowledgement signal to the modulator;
• and
• processing a packet, comprising data, from a second received spread-spectrum signal.

A base-band processor, for use in a code-division-multiple-access (CDMA) wireless handset having a spread-spectrum modulator and a spread-spectrum demodulator, the base-band processor, comprising:

• an acknowledgment detector, coupled to the demodulator, for detecting an acknowledgment in a received spread-spectrum signal;
• an encoder, for encoding data;
• an interleaver, coupled to the encoder, for interleaving encoded data;
• a preamble generator for generating a preamble;
• a multiplexer, coupled to the interleaver and to the preamble generator, for multiplexing the interleaved data and the preamble;
• a packet formatter, coupled to the multiplexer, for formatting the multiplexed data and preamble into one or more packets;
• and
• a controller coupled to the acknowledgment detector and coupled for controlling the modulator, the preamble generator, the multiplexer and the packet formatter, such that in operation the base-band processor is for performing the following steps:
• generating and outputting to the modulator a plurality of packets comprising a sequence of coded preamble signals at sequentially increasing discrete power levels;
• detecting an acknowledgement in a received spread-spectrum signal;
• and
• upon detection of the acknowledgement, outputting a packet comprising data to the modulator for transmission over a random access wireless channel.

A method of operation of a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) with a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations, with each remote station (RS) having an RS-spread spectrum transmitter and an RS-spread-spectrum receiver, the method comprising the steps of:

• transmitting a broadcast common-synchronization channel, from the BS-spread-spectrum transmitter located at the base station to the plurality of remote stations;
• receiving at a first RS-spread-spectrum receiver the broadcast common-synchronization channel, and determining a plurality of parameters required for transmission to the base station;
• transmitting from a first RS-spread-spectrum transmitter a first preamble at a first discrete power level;
• if no acknowledgment corresponding to the previously transmitted preamble is received at the first RS-spread-spectrum receiver by a time following the transmission of the first preamble, transmitting from the first RS-spread-spectrum transmitter a second preamble at a second discrete power level that is higher than the first discrete power level;
• receiving the second preamble, at a detected-power level, at the BS-spread-spectrum receiver;
• transmitting an acknowledgment of the received preamble from the BS-spread-spectrum transmitter;
• receiving the acknowledgment at the first RS-spread-spectrum receiver;
• and
• transmitting a spread-spectrum signal having data from the first RS-spread spectrum transmitter to the BS-spread-spectrum receiver, responsive to the receipt of the acknowledgment.

A method of communication through a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) with a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver, and a plurality of remote stations, with each remote station (RS) having an RS-spread spectrum transmitter and an RS-spread-spectrum receiver, the method comprising the steps of:

• receiving a broadcast common-synchronization channel from the BS-spread-spectrum transmitter located at the RS-spread-spectrum receiver of one of the remote stations, and determining a plurality of parameters required for transmission to the base station;
• transmitting a preamble at a discrete power level from the RS-spread-spectrum transmitter of the one remote station;
• listening for an acknowledgment corresponding to the transmitted preamble at the RS-spread-spectrum receiver of the one remote station;
• if an acknowledgment is not received, upon expiration of a predetermined interval, following the transmission of the preamble, increasing power level to a new discrete power level, and repeating the transmitting step and continuing the listening step;
• upon receiving an acknowledgment at the RS-spread-spectrum receiver of the one remote station, ceasing preamble transmission and transmitting a spread-spectrum signal having data from the RS-spread-spectrum transmitter of the one remote station, for the BS-spread-spectrum receiver.

A method of transferring packet data for a mobile station (MS) with an MS receiver and an MS transmitter, comprising:

• receiving at the MS receiver a broadcast common channel from a base station;
• determining a plurality of parameters required for transmission to the base station;
• spreading an access preamble selected from a set of predefined preambles;
• transmitting from the MS transmitter the spread access preamble, at a first discrete power level;
• if NO acknowledgement corresponding to the access preamble is detected, transmitting a spread access preamble from the MS transmitter at a second discrete power level higher than the first discrete power level;
• and
• upon detecting an acknowledgement corresponding to a transmitted access preamble, ceasing preamble transmission and transmitting the packet data from the MS transmitter.

A code-division-multiple-access (CDMA) wireless handset, comprising:

• a CDMA transmitter;
• a CDMA receiver;
• and
• a controller coupled to the CDMA receiver for responding to signals received via the CDMA receiver and coupled for controlling the CDMA transmitter, such that in operation the CDMA handset is for performing the following steps:
• spreading an access preamble selected from a set of predefined preambles;
• transmitting the spread access preamble, at a first discrete power level to a base station;
• if NO acknowledgement corresponding to the access preamble is detected, transmitting a spread access preamble from the MS transmitter at a second discrete power level higher than the first discrete power level;
• and
• upon detecting an acknowledgement corresponding to a transmitted access preamble, ceasing preamble transmission and transmitting packet data from the MS transmitter.